Name: conjugative mating assays for sequence-specific analysis of transfer proteins involved in bacterial conjugation
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Description: Watch this Scientific Journal Video about Conjugative Mating Assays for Sequence-specific Analysis of Transfer Proteins Involved in Bacterial Conjugation at JoVE.com

This research was supported by a Discovery Grant from the Natural Sciences &#38; Engineering Council of Canada (NSERC).

1. Generation of DNA Constructs
<ol>
	<li>Designing Oligomers for Homologous Recombination of the Target Gene
	<ol>
		<li>Design a single 55-72 bp forward oligomer as follows: (a) pick a 19-32 bp long nucleotide sequence that is homologous to a DNA sequence in the region 10-100 bp upstream of the 5&#39; start site of the chloramphenicol acetyltransferase gene in the commercial pBAD33 plasmid,32 and (b) select a 36-54 bp long nucleotide sequence homologous to a region 10-150 bp downstream of ...

<ol>
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J. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Biological+diversity+of+prokaryotic+type+IV+secretion+systems.">Biological diversity of prokaryotic type IV secretion systems.</a> Microbiol Mol Biol Rev. 73 (4), 775-808 (2009).</li><li>Lawley, T. D., Klimke, W. A., Gubbins, M. J., Frost, L. S. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=F+factor+conjugation+is+a+true+type+IV+secretion+system.">F factor conjugation is a true type IV secretion system.</a> FEMS Microbiol Lett. 224 (1), 1-15 (2003).</li><li>Lederberg, J., Tatum, E. L. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Gene+Recombination+in+Escherichia+Coli.">Gene Recombination in Escherichia Coli.</a> Nature. 158 (4016), 558-558 (1946).</li><li>Smillie, C., Garcillan-Barcia, M. P., Francia, M. V., Rocha, E. P. C., de la Cruz, F. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Mobility+of+Plasmids.">Mobility of Plasmids.</a> Microbiol Mol Biol Rev. 74 (3), 434-452 (2010).</li><li>Willetts, N., Skurray, R. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=The+Conjugation+System+of+F-Like+Plasmids.">The Conjugation System of F-Like Plasmids.</a> Annu Rev Genet. 14 (1), 41-76 (1980).</li><li>Frost, L. S., Ippen-Ihler, K., Skurray, R. A. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Analysis+of+the+sequence+and+gene+products+of+the+transfer+region+of+the+F+sex+factor.">Analysis of the sequence and gene products of the transfer region of the F sex factor.</a> Microbiol Rev. 58 (2), 162-210 (1994).</li><li>Audette, G. F., Manchak, J., Beatty, P., Klimke, W. A., Frost, L. S. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Entry+exclusion+in+F-like+plasmids+requires+intact+TraG+in+the+donor+that+recognizes+its+cognate+TraS+in+the+recipient.">Entry exclusion in F-like plasmids requires intact TraG in the donor that recognizes its cognate TraS in the recipient.</a> Microbiology. 153, 442-451 (2007).</li><li>Christie, P. J., Atmakuri, K., Krishnamoorthy, V., Jakubowski, S., Cascales, E. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Biogenesis,+Architecture,+and+Function+of+Bacterial+Type+Iv+Secretion+Systems.">Biogenesis, Architecture, and Function of Bacterial Type Iv Secretion Systems.</a> Annu Rev Microbiol. 59 (1), 451-485 (2005).</li><li>Christie, P. J. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Type+IV+secretion:+the+Agrobacterium+VirB/D4+and+related+conjugation+systems.">Type IV secretion: the Agrobacterium VirB/D4 and related conjugation systems.</a> Biochim Biophys Acta - Mol Cell Res. 1694 (1-3), 219-234 (2004).</li><li>Bhatty, M., Laverde Gomez, J. a., Christie, P. J. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=The+expanding+bacterial+type+IV+secretion+lexicon.">The expanding bacterial type IV secretion lexicon.</a> Res Microbiol. 164 (6), 620-639 (2013).</li><li>Christie, P. J., Cascales, E. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Structural+and+dynamic+properties+of+bacterial+Type+IV+secretion+systems+(Review).">Structural and dynamic properties of bacterial Type IV secretion systems (Review).</a> Mol Membr Biol. 22 (1-2), 51-61 (2005).</li><li>Christie, P. J. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Type+IV+secretion:+Intercellular+transfer+of+macromolecules+by+systems+ancestrally+related+to+conjugation+machines.">Type IV secretion: Intercellular transfer of macromolecules by systems ancestrally related to conjugation machines.</a> Mol Microbiol. 40 (2), 294-305 (2001).</li><li>Christie, P. J., Whitaker, N., Gonz&#225;lez-Rivera, C. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Mechanism+and+structure+of+the+bacterial+type+IV+secretion+systems.">Mechanism and structure of the bacterial type IV secretion systems.</a> Biochim Biophys Acta. 1843 (8), 1578-1591 (2014).</li><li>Cascales, E. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=The+type+VI+secretion+toolkit.">The type VI secretion toolkit.</a> EMBO Rep. 9, 735 (2008).</li><li>Silverman, J. M., Brunet, Y. R., Cascales, E., Mougous, J. D. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Structure+and+Regulation+of+the+Type+VI+Secretion+System.">Structure and Regulation of the Type VI Secretion System.</a> Annu Rev Microbiol. 66 (1), 453-472 (2012).</li><li>Chandran, V., et al. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Structure+of+the+outer+membrane+complex+of+a+type+IV+secretion+system.">Structure of the outer membrane complex of a type IV secretion system.</a> Nature. 462 (7276), 1011-1015 (2009).</li><li>Rivera-Calzada, A., et al. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Structure+of+a+bacterial+type+IV+secretion+core+complex+at+subnanometre+resolution.">Structure of a bacterial type IV secretion core complex at subnanometre resolution.</a> EMBO J. 32 (8), 1195-1204 (2013).</li><li>Waksman, G., Fronzes, R. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Molecular+architecture+of+bacterial+type+IV+secretion+systems.">Molecular architecture of bacterial type IV secretion systems.</a> Trends Biochem Sci. 35, 691 (2010).</li><li>Fronzes, R., Christie, P. J., Waksman, G. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=The+structural+biology+of+type+IV+secretion+systems.">The structural biology of type IV secretion systems.</a> Nat Rev Microbiol. 7 (10), 703-714 (2009).</li><li>Kaplan, M., et al. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Probing+a+cell-embedded+megadalton+protein+complex+by+DNP-supported+solid-state+NMR.">Probing a cell-embedded megadalton protein complex by DNP-supported solid-state NMR.</a> Nat Methods. 12 (7), 5-9 (2015).</li><li>Guyer, M. S., Reed, R. R., Steitz, J. A., Low, K. B. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Identification+of+a+sex-factor-affinity+site+in+E.+coli+as+gamma+delta.">Identification of a sex-factor-affinity site in E. coli as gamma delta.</a> Cold Spring Harb Symp Quant Biol. 45, 135-140 (1981).</li><li>Anthony, K. G., Sherburne, C., Sherburne, R., Frost, L. S. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=The+role+of+the+pilus+in+recipient+cell+recognition+during+bacterial+conjugation+mediated+by+F-like+plasmids.">The role of the pilus in recipient cell recognition during bacterial conjugation mediated by F-like plasmids.</a> Mol Microbiol. 13 (6), 939-953 (1994).</li><li>Jobling, M. G., Holmes, R. K. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Construction+of+vectors+with+the+pl5a+replicon,+kanamycin+resistance,+inducible+lacZ&#945;+and+pUC18+or+pUC19+multiple+cloning+sites.">Construction of vectors with the pl5a replicon, kanamycin resistance, inducible lacZ&#945; and pUC18 or pUC19 multiple cloning sites.</a> Nucleic Acids Res. 18 (17), 5315 (1990).</li><li>Guzman, L. M., Belin, D., Carson, M. J., Beckwith, J. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Tight+regulation,+modulation,+and+high-level+expression+by+vectors+containing+the+arabinose+P(BAD)+promoter.">Tight regulation, modulation, and high-level expression by vectors containing the arabinose P(BAD) promoter.</a> J Bacteriol. 177 (14), 4121-4130 (1995).</li><li>Yu, D., et al. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=An+efficient+recombination+system+for+chromosome+engineering+in+Escherichia+coli.">An efficient recombination system for chromosome engineering in Escherichia coli.</a> Proc Natl Acad Sci U S A. 97 (11), 5978-5983 (2009).</li><li>Lawley, T. D., Gilmour, M. W., Gunton, J. E., Standeven, L. J., Taylor, D. E. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Functional+and+Mutational+Analysis+of+Conjugative+Transfer+Region+1+(Tra1)+from+the+IncHI1+Plasmid+R27.">Functional and Mutational Analysis of Conjugative Transfer Region 1 (Tra1) from the IncHI1 Plasmid R27.</a> J Bacteriol. 184 (8), 2173-2180 (2002).</li><li>Elton, T. C., Holland, S. J., Frost, L. S., Hazes, B. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=F-Like+Type+IV+Secretion+Systems+Encode+Proteins+with+Thioredoxin+Folds+That+Are+Putative+DsbC+Homologues.">F-Like Type IV Secretion Systems Encode Proteins with Thioredoxin Folds That Are Putative DsbC Homologues.</a> J Bacteriol. 187 (24), 8267-8277 (2005).</li><li>Hazes, B., Frost, L. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Towards+a+systems+biology+approach+to+study+type+II/IV+secretion+systems.">Towards a systems biology approach to study type II/IV secretion systems.</a> Biochim Biophys Acta. 1778, 1839-1850 (2008).</li><li>Lento, C., Ferraro, M., Wilson, D., Audette, G. F., Tsolis, R. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=HDX-MS+and+deletion+analysis+of+the+type+4+secretion+system+protein+TraF+from+the+Escherichia+coli+F+plasmid.">HDX-MS and deletion analysis of the type 4 secretion system protein TraF from the Escherichia coli F plasmid.</a> FEBS Lett. 590 (3), 376-386 (2016).</li><li>Audette, G. F., Van Schaik, E. J., Hazes, B., Irvin, R. T. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=DNA-binding+protein+nanotubes:+Learning+from+nature's+nanotech+examples.">DNA-binding protein nanotubes: Learning from nature's nanotech examples.</a> Nano Lett. 4, 1897-1902 (2004).</li><li>Harris, R. L., Silverman, P. A. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Tra+proteins+characteristic+of+F-like+type+IV+secretion+systems+constitute+an+interaction+group+by+yeast+two-hybrid+analysis.">Tra proteins characteristic of F-like type IV secretion systems constitute an interaction group by yeast two-hybrid analysis.</a> J Bacteriol. 186 (16), 5480-5485 (2004).</li><li>Moore, D., et al. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Characterization+of+the+F-Plasmid+Conjugative+Transfer+Gene+traU.">Characterization of the F-Plasmid Conjugative Transfer Gene traU.</a> J Bacteriol. 172 (8), 4263-4270 (1990).</li><li>Anthony, K. G., Sherburne, C., Sherburne, R., Frost, L. S. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=The+role+of+the+pilus+in+recipient+cell+recognition+during+bacterial+conjugation+mediated+by+F-like+plasmids.">The role of the pilus in recipient cell recognition during bacterial conjugation mediated by F-like plasmids.</a> Mol Microbiol. 13 (6), 939-953 (1994).</li><li>Klimke, W. A., Frost, L. S. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Genetic+analysis+of+the+role+of+the+transfer+gene,+traN,+of+the+F+and+R100-1+plasmids+in+mating+pair+stabilization+during+conjugation.">Genetic analysis of the role of the transfer gene, traN, of the F and R100-1 plasmids in mating pair stabilization during conjugation.</a> J Bacteriol. 180 (16), 4036-4043 (1998).</li><li>Jiang, W., Marraffini, L. A. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=CRISPR-Cas:+New+Tools+for+Genetic+Manipulations+from+Bacterial+Immunity+Systems.">CRISPR-Cas: New Tools for Genetic Manipulations from Bacterial Immunity Systems.</a> Annu Rev Microbiol. 69 (1), 209-228 (2015).</li><li>Dahlberg, C., Bergstrom, M., Andreasen, M., Christensen, B. B., Molin, S., Hermansson, M. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Interspecies+bacterial+conjugation+by+plasmids+from+marine+environments+visualized+by+gfp+expression.">Interspecies bacterial conjugation by plasmids from marine environments visualized by gfp expression.</a> Mol Biol Evol. 15 (4), 385-390 (1998).</li></ol>

Bacterial conjugation process provides a means by which bacteria can spread genes providing an evolutionary advantage for growth in challenging environments, such as the spread of antibiotic resistance markers. Because many of the conjugative plasmids are so large,12 functional studies on the proteins involved in assembly of the transfer apparatus through mutation of target genes on the conjugative plasmid itself are unwieldy. The protocols detailed herein provide a means by which one can more readily assess t...

The transfer of genes and proteins at the micro-organismal level plays a central role in bacterial survival and evolution as well as infection processes. The exchange of DNA between bacteria or between a bacterium and a cell can be achieved through transformation, conjugation or vector transduction.1,2 Conjugation is unique in comparison to transformation and transduction in that during conjugation between gram-negative bacteria such as Escherichia coli, the transfer of DNA occurs in a donor-controlled fashion whereby a complex macromolecular system connects donor and recipient cells. Conjugation is also the most direct way in which bacterial cells interact with host cells to inject genes, proteins or chemicals in to host systems.3 Quite often, the transfer of such agents has remarkable effects on the host, ranging from pathogenesis and carcinogenesis to host evolution and adaptation. It has been shown that conjugative recombination increases the rate of adaptation 3-fold in bacteria with high mutation rates under conditions of environmental stress.4 Moreover, conjugation is by far the most common route through which antibiotic resistance genes in bacterial strains are spread.5,6
Microorganisms have evolved specialized secretion systems to support the transfer of macromolecules across cellular membranes; there are currently 9 types of secretion systems (TSSs) in gram negative bacteria that have been described: T1SS, T2SS, T3SS, T4SS, T5SS, T6SS, T7SS, as well as the Sec (secretion) and Tat (two-arginine translocation) pathways.7,8 Each type of secretion system is further divided into different subtypes, a necessity due to diversity of proteins and the distinctiveness of pathways involved, in different bacterial strains. For example, in the type IV secretion system (T4SS), the Ti and Cag systems facilitate effector transport whereas the F-plasmid, R27 and pKM101 T4SSs facilitate transfer of a conjugative plasmid.7,9,10 A detailed understanding of the mechanisms by which organisms assemble their respective secretion systems from their component proteins and share cellular contents with a recipient or their surrounding environment is an important factor in development of targeted strategies to combat pathogenic microorganisms and processes of cellular infection.
Following the initial identification bacterial conjugation in E. coli by Lederberg &#38; Tatum,11 a large number of mobile and conjugative plasmids have been identified and characterized.12 Such mobile plasmids show considerable range is size (from 1 to over 200 kilobases (kb)), however all mobile plasmids contain a relaxase, which recognizes the origin of transfer (oriT) thereby enabling transmission of the plasmid. Conjugative plasmids further encode genes for assembly of a functional T4SS as well as a type IV coupling protein.12 For example the 100 kb F plasmid of E. coli encodes all the conjugative genes within a 33.3 kB transfer (tra) region.13 The genes in the tra region of the F plasmid encode all proteins that facilitate pilus formation, mating pair formation (Mpf), DNA transfer and exclusion functions during conjugative plasmid transfer.10,14,15 A significant body of knowledge is available for conjugative T4SSs, however detailed structural studies of the conjugative proteins and complexes are only more recently becoming available.16-28
In order to assemble a comprehensive view of the conjugative process, a coupling of detailed structural studies to mutational analyses of conjugative transfer proteins is required. This can be achieved through conjugative mating assays. For the F plasmid, each protein encoded within the tra region plays a role in the F-mediated conjugation; therefore, the knockout/deletion of a transfer gene will abolish the conjugative capacity of the cell (Figure 1). While smaller mobile plasmids are more conducive to standard deletion procedures, for larger conjugative plasmids such as F, gene knockouts are more readily achieved via homologous recombination where the target gene is replaced with one conveying a distinct antibiotic resistance gene. In the current protocol, we employ homologous recombination to replace a transfer gene of interest with chloramphenicol acetyltransferase (CAT) in the 55 kb F plasmid derivative pOX38-Tc;29,30 the resultant knockout plasmid, pOX38-Tc &#916;gene::Cm, facilitates resistance to the presence of chloramphenicol (Cm) in the growth media. Donor cells harboring pOX38-Tc &#916;gene::Cm are unable to affect conjugative DNA transfer/mating as observed through the use of a mating assay; the mating efficiency of a pOX38-Tc &#916;gene::Cm donor cell and a normal recipient will decrease or, more often, be abolished. Conjugative transfer of the pOX38-Tc &#916;gene::Cm plasmid can be restored via a small recovery plasmid harboring the targeted transfer gene. This recovery plasmid can be one that provides constitutive expression, such as plasmid pK184 (pK184-gene),31 or one that provides inducible expression so long as that plasmid properly targets the gene to the correct location within the cell (cytoplasm or periplasm). Consequently, in mating assays between this new donor (harboring pOX38-Tc &#916;gene::Cm + pK184-gene plasmids) and a recipient cell, the mating efficiency is expected to restore to nearly that of a normal donor-recipient mating assay. This system enables one to probe the function of the knocked out gene through the generation of a series of pK184-gene constructs (deletions or point mutations) and testing each construct&#39;s ability to restore the mating capacity of the pOX38-Tc &#916;gene::Cm harboring donor cells.

<table border="0" cellpadding="0" cellspacing="0" width="762">
	<tbody>
		<tr height="22">
			<td height="22" style="height:22px;width:255px;">GeneJet Plasmid Mini-Prep Kit</td>
			<td style="width:165px;">Fisher Scientific</td>
			<td style="width:131px;">K0503</td>
			<td style="width:212px;"></td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;width:255px;">GeneJet Gel Extraction Kit</td>
			<td style="width:165px;">Fisher Scientific</td>
			<td style="width:131px;">K0692</td>
			<td></td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;width:255px;">GeneJet PCR Purification Kit</td>
			<td style="width:165px;">Fisher Scientific</td>
			<td style="width:131px;">K0702</td>
			<td style="width:212px;"></td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;">Q5 Site-Directed Mutagenesis Kit</td>
			<td>New England Biolabs</td>
			<td>E0554S</td>
			<td></td>
		</tr>
		<tr height="20">
			<td height="20" style="height:20px;">Broad Range DNA Ladder</td>
			<td>New England Biolabs</td>
			<td>N0303A</td>
			<td></td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;width:255px;">Petri Dishes</td>
			<td style="width:165px;">Fisher Scientific</td>
			<td style="width:131px;">FB0875713</td>
			<td style="width:212px;"></td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;width:255px;">Electroporator</td>
			<td style="width:165px;">Eppendorf</td>
			<td style="width:131px;">4309000027</td>
			<td style="width:212px;"></td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;width:255px;">Electroporation cuvettes</td>
			<td style="width:165px;">Fisher Scientific</td>
			<td style="width:131px;">FB101</td>
			<td style="width:212px;">Cuvettes have a 1 mm gap.</td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;width:255px;">Enzymes</td>
			<td style="width:165px;"></td>
			<td style="width:131px;"></td>
			<td style="width:212px;"></td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;width:255px;">AvaI</td>
			<td style="width:165px;">New England Biolabs</td>
			<td style="width:131px;">R0152S</td>
			<td style="width:212px;"></td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;width:255px;">EcoRI</td>
			<td style="width:165px;">New England Biolabs</td>
			<td style="width:131px;">R0101S</td>
			<td style="width:212px;"></td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;width:255px;">HindIII</td>
			<td style="width:165px;">New England Biolabs</td>
			<td style="width:131px;">R0104L</td>
			<td style="width:212px;"></td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;width:255px;">NdeI</td>
			<td style="width:165px;">New England Biolabs</td>
			<td style="width:131px;">R0111S</td>
			<td style="width:212px;"></td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;width:255px;">Phusion DNA Polymerase</td>
			<td style="width:165px;">New England Biolabs</td>
			<td style="width:131px;">M0530L</td>
			<td style="width:212px;"></td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;width:255px;">T4 DNA Ligase</td>
			<td style="width:165px;">New England Biolabs</td>
			<td style="width:131px;">M0202S</td>
			<td style="width:212px;"></td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;width:255px;">DpnI</td>
			<td style="width:165px;">New England Biolabs</td>
			<td style="width:131px;">R0176S</td>
			<td style="width:212px;"></td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;width:255px;">Antibiotics</td>
			<td style="width:165px;"></td>
			<td style="width:131px;"></td>
			<td style="width:212px;">Final Concentrations</td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;width:255px;">Chloramphenicol (Cm)</td>
			<td style="width:165px;">Fisher Scientific</td>
			<td style="width:131px;">BP904-100</td>
			<td style="width:212px;">20 &#181;g/mL</td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;width:255px;">Kanamycin (Km)</td>
			<td style="width:165px;">BioBasic Inc.</td>
			<td style="width:131px;">DB0286</td>
			<td style="width:212px;">50 &#181;g/mL</td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;width:255px;">Nalidixic acid (Nal)</td>
			<td style="width:165px;">Sigma-Aldrich</td>
			<td style="width:131px;">N8878-25G</td>
			<td style="width:212px;">10 &#181;g/mL</td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;width:255px;">Rifampicin (Rif)</td>
			<td style="width:165px;">Calbiochem</td>
			<td style="width:131px;">557303</td>
			<td style="width:212px;">20 &#181;g/mL</td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;width:255px;">Tetracycline (Tc)</td>
			<td style="width:165px;">Fisher Scientific</td>
			<td style="width:131px;">BP912-100</td>
			<td style="width:212px;">10 &#181;g/mL</td>
		</tr>
		<tr height="22">
			<td height="22" style="height:22px;width:255px;">Streptomycin (Sm)</td>
			<td style="width:165px;">Fisher Scientific</td>
			<td style="width:131px;">BP910-50</td>
			<td style="width:212px;">50 &#181;g/mL</td>
		</tr>
	</tbody>
</table>

conjugative mating assays for sequence-specific analysis of transfer proteins involved in bacterial conjugation

The transfer of genetic material by bacterial conjugation is a process that takes place via complexes formed by specific transfer proteins. In Escherichia coli, these transfer proteins make up a DNA transfer machinery known as the mating pair formation, or DNA transfer complex, which facilitates conjugative plasmid transfer. The objective of this paper is to provide a method that can be used to determine the role of a specific transfer protein that is involved in conjugation using a series of deletions and/or point mutations in combination with mating assays. The target gene is knocked out on the conjugative plasmid and is then provided in trans through the use of a small recovery plasmid harboring the target gene. Mutations affecting the target gene on the recovery plasmid can reveal information about functional aspects of the target protein that result in the alteration of mating efficiency of donor cells harboring the mutated gene. Alterations in mating efficiency provide insight into the role and importance of the particular transfer protein, or a region therein, in facilitating conjugative DNA transfer. Coupling this mating assay with detailed three-dimensional structural studies will provide a comprehensive understanding of the function of the conjugative transfer protein as well as provide a means for identifying and characterizing regions of protein-protein interaction.

The process of F plasmid-driven bacterial conjugation is a coordinated process that involves transfer proteins within the tra region of the F-plasmid that assembles a T4SS to facilitate pilus synthesis and conjugative DNA transfer. The protein TraF (GenBank accession # BAA97961; UniProt ID P14497) is required for conjugative F-pilus formation.10,14,35-37 The protein contains a C-terminal thioredoxin-like domain, though it does not have the catalyt...

Watch this Scientific Journal Video about Conjugative Mating Assays for Sequence-specific Analysis of Transfer Proteins Involved in Bacterial Conjugation at JoVE.com

Conjugative Mating Assays for Sequence-specific Analysis of Transfer Proteins Involved in Bacterial Conjugation

Here, we present a protocol to knockout a gene of interest involved in plasmid conjugation and subsequently analyze the impact of its absence using mating assays. The function of the gene is further explored to a specific region of its sequence using deletion or point mutations.

The transfer of genetic material by bacterial conjugation is a process that takes place via complexes formed by specific transfer proteins. In Escherichia ...

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