2b59
The type II cohesin dockerin complexThe type II cohesin dockerin complex
Structural highlights
Evolutionary Conservation Check, as determined by ConSurfDB. You may read the explanation of the method and the full data available from ConSurf. Publication Abstract from PubMedBacterial cell-surface attachment of macromolecular complexes maintains the microorganism in close proximity to extracellular substrates and allows for optimal uptake of hydrolytic byproducts. The cellulosome is a large multienzyme complex used by many anaerobic bacteria for the efficient degradation of plant cell-wall polysaccharides. The mechanism of cellulosome retention to the bacterial cell surface involves a calcium-mediated protein-protein interaction between the dockerin (Doc) module from the cellulosomal scaffold and a cohesin (Coh) module of cell-surface proteins located within the proteoglycan layer. Here, we report the structure of an ultra-high-affinity (K(a) = 1.44 x 10(10) M(-1)) complex between type II Doc, together with its neighboring X module from the cellulosome scaffold of Clostridium thermocellum, and a type II Coh module associated with the bacterial cell surface. Identification of X module-Doc and X module-Coh contacts reveal roles for the X module in Doc stability and enhanced Coh recognition. This extremely tight interaction involves one face of the Coh and both helices of the Doc and comprises significant hydrophobic character and a complementary extensive hydrogen-bond network. This structure represents a unique mechanism for cell-surface attachment in anaerobic bacteria and provides a rationale for discriminating between type I and type II Coh modules. Mechanism of bacterial cell-surface attachment revealed by the structure of cellulosomal type II cohesin-dockerin complex.,Adams JJ, Pal G, Jia Z, Smith SP Proc Natl Acad Sci U S A. 2006 Jan 10;103(2):305-10. Epub 2005 Dec 29. PMID:16384918[1] From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine. References |
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