1bgs
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RECOGNITION BETWEEN A BACTERIAL RIBONUCLEASE, BARNASE, AND ITS NATURAL INHIBITOR, BARSTAR
OverviewOverview
BACKGROUND: Protein-protein recognition is fundamental to most biological, processes. The information we have so far on the interfaces between, proteins comes largely from several protease-inhibitor and, antigen-antibody complexes. Barnase, a bacterial ribonuclease, and, barstar, its natural inhibitor, form a tight complex which provides a good, model for the study and design of protein-protein non-covalent, interactions. RESULTS: Here we report the structure of a complex between, barnase and a fully functional mutant of barstar determined by X-ray, analysis. Barstar is composed of three parallel alpha-helices stacked, against a three-stranded parallel, beta-sheet, and sterically blocks the, active site of the enzyme with an alpha-helix and adjacent loop. The, buried surface in the interface between the two molecules totals 1630 A2., The barnase-barstar complex is predominantly stabilized by charge, interactions involving positive charges in the active site of the enzyme., Asp39 of barstar binds to the phosphate-binding site of barnase, mimicking, enzyme-substrate interactions. CONCLUSION: The phosphate-binding site of, the enzyme is the anchor point for inhibitor binding. We propose that this, is also likely to be the case for other ribonuclease inhibitors.
About this StructureAbout this Structure
1BGS is a Protein complex structure of sequences from Bacillus amyloliquefaciens. Full crystallographic information is available from OCA.
ReferenceReference
Recognition between a bacterial ribonuclease, barnase, and its natural inhibitor, barstar., Guillet V, Lapthorn A, Hartley RW, Mauguen Y, Structure. 1993 Nov 15;1(3):165-76. PMID:16100951
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