1ohz
From Proteopedia
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COHESIN-DOCKERIN COMPLEX FROM THE CELLULOSOME OF CLOSTRIDIUM THERMOCELLUM
Overview
The utilization of organized supramolecular assemblies to exploit the, synergistic interactions afforded by close proximity, both for enzymatic, synthesis and for the degradation of recalcitrant substrates, is an, emerging theme in cellular biology. Anaerobic bacteria harness a, multiprotein complex, termed the "cellulosome," for efficient degradation, of the plant cell wall. This megadalton catalytic machine organizes an, enzymatic consortium on a multifaceted molecular scaffold whose "cohesin", domains interact with corresponding "dockerin" domains of the enzymes., Here we report the structure of the cohesin-dockerin complex from, Clostridium thermocellum at 2.2-A resolution. The data show that the, beta-sheet cohesin domain interacts predominantly with one of the helices, of the dockerin. Whereas the structure of the cohesin remains essentially, unchanged, the loop-helix-helix-loop-helix motif of the dockerin undergoes, conformational change and ordering compared with its solution structure, although the classical 12-residue EF-hand coordination to two calcium ions, is maintained. Significantly, internal sequence duplication within the, dockerin is manifested in near-perfect internal twofold symmetry, suggesting that both "halves" of the dockerin may interact with cohesins, in a similar manner, thus providing a higher level of structure to the, cellulosome and possibly explaining the presence of "polycellulosomes.", The structure provides an explanation for the lack of cross-species, recognition between cohesin-dockerin pairs and thus provides a blueprint, for the rational design, construction, and exploitation of these catalytic, assemblies.
About this Structure
1OHZ is a Protein complex structure of sequences from Clostridium thermocellum with , , and as ligands. Active as Endo-1,4-beta-xylanase, with EC number 3.2.1.8 Known structural/functional Site: . Full crystallographic information is available from OCA.
Reference
Cellulosome assembly revealed by the crystal structure of the cohesin-dockerin complex., Carvalho AL, Dias FM, Prates JA, Nagy T, Gilbert HJ, Davies GJ, Ferreira LM, Romao MJ, Fontes CM, Proc Natl Acad Sci U S A. 2003 Nov 25;100(24):13809-14. Epub 2003 Nov 17. PMID:14623971
Page seeded by OCA on Sun Feb 3 09:58:20 2008
