improving-success-rate-protein-crystallization-random-microseed

Improving the Success Rate of Protein Crystallization by Random Microseed Matrix Screening

Random microseed matrix screening  (rMMS) is a protein crystallization technique in which seed crystals are added  to random screens. By increasing the ...

University of Bristol

A new alkaloid, 5-bromo-8-methoxy-1-methyl-beta-carboline (1), has been isolated from the New Zealand marine bryozoan Pterocella Vesiculosa. Structural elucidation was achieved through NMR spectroscopic and mass spectrometric analysis, and a single-crystal X-ray diffraction analysis of 1 was performed. The biological activity of 1 was assessed against P388 murine leukemia cells and three microorganisms and compared with that of a number of related beta-carboline alkaloids.

5-Bromo-8-methoxy-1-methyl-beta-carboline, an alkaloid from the New Zealand marine bryozoan Pterocella vesiculosa.

The release of polysaccharide from the plant cell wall is a key process to release the stored energy from plant biomass. Within the ruminant digestive system, a host of commensal microorganisms speed the breakdown of plant cell matter releasing fermentable sugars. The presence of phenolic compounds, most notably ferulic acid (FA), esterified within the cell wall is thought to pose a significant impediment to the degradation of the plant cell wall. The structure of a FA esterase from the ruminant bacterium Butyrivibrio proteoclasticus has been determined in two different space groups, in both the apo-form, and the ligand bound form with FA located in the active site. The structure reveals a new lid domain that has no structural homologues in the PDB. The flexibility of the lid domain is evident by the presence of three different conformations adopted by different molecules in the crystals. In the FA-bound structures, these conformations show sequential binding and closing of the lid domain over the substrate. Enzymatic activity assays demonstrate a broad activity against plant-derived hemicellulose, releasing at least four aromatic compounds including FA, coumaric acid, coumarin-3-carboxylic acid, and cinnamic acid. The rumen is a complex ecosystem that efficiently degrades plant biomass and the genome of B. proteoclasticus contains greater than 130 enzymes, which are potentially involved in this process of which Est1E is the first to be well characterized.

Structural and functional characterization of a promiscuous feruloyl esterase (Est1E) from the rumen bacterium Butyrivibrio proteoclasticus.

Butyrivibrio proteoclasticus is a significant component of the microbial population of the rumen of dairy cattle. It is a xylan-degrading organism whose genome encodes a large number of open reading frames annotated as fiber-degrading enzymes. We have determined the three-dimensional structure of Est2A, an acetyl xylan esterase from B. proteoclasticus, at 2.1 Ã… resolution, along with the structure of an inactive mutant (H351A) at 2.0 Ã… resolution. The structure reveals two domains-a C-terminal SGNH domain and an N-terminal jelly-roll domain typical of CE2 family structures. The structures are accompanied by experimentally determined enzymatic parameters against two model substrates, para-nitrophenyl acetate and para-nitrophenyl butyrate. The suite of fiber-degrading enzymes produced by B. proteoclasticus provides a rich source of new enzymes of potential use in industrial settings.

Marisa Till

School of Biochemistry

University of Bristol

Improving the Success Rate of Protein Crystallization by Random Microseed Matrix Screening