4B9G

Structure of CssB subunit complemented with donor strand from CssA subunit of enterotoxigenic Escherichia coli colonization factor CS6

Summary for 4B9G

• Entry DOI: 10.2210/pdb4b9g/pdb
• Related: 4B9G 4B9I 4B9J
• Descriptor: CS6 FIMBRIAL SUBUNIT B, CS6 FIMBRIAL SUBUNIT A (2 entities in total)
• Functional Keywords: cell adhesion, diarrheal disease, fimbriae, fusion protein
• Biological source: ESCHERICHIA COLI
• Cellular location: Fimbrium: P53508
• Total number of polymer chains: 2
• Total formula weight: 35114.57

Authors

Roy, S.P.,Rahman, M.M.,Yu, X.D.,Tuittila, M.,Knight, S.D.,Zavialov, A.V. (deposition date: 2012-09-04, release date: 2012-11-07, Last modification date: 2024-05-08)

Primary citation

Roy, S.P.,Rahman, M.M.,Yu, X.D.,Tuittila, M.,Knight, S.D.,Zavialov, A.V.
Crystal Structure of Enterotoxigenic Escherichia Coli Colonization Factor Cs6 Reveals a Novel Type of Functional Assembly.
Mol.Microbiol., 86:1100-, 2012

PubMed Abstract: Coli surface antigen 6 (CS6) is a widely expressed enterotoxigenic Escherichia coli (ETEC) colonization factor that mediates bacterial attachment to the small intestinal epithelium. CS6 is a polymer of two protein subunits CssA and CssB, which are secreted and assembled on the cell surface via the CssC/CssD chaperone usher (CU) pathway. Here, we present an atomic resolution model for the structure of CS6 based on the results of X-ray crystallographic, spectroscopic and biochemical studies, and suggest a mechanism for CS6-mediated adhesion. We show that the CssA and CssB subunits are assembled alternately in linear fibres by the principle of donor strand complementation. This type of fibre assembly is novel for CU assembled adhesins. We also show that both subunits in the fibre bind to receptors on epithelial cells, and that CssB, but not CssA, specifically recognizes the extracellular matrix protein fibronectin. Taken together, structural and functional results suggest that CS6 is an adhesive organelle of a novel type, a hetero-polyadhesin that is capable of polyvalent attachment to different receptors.

PubMed: 23046340
DOI: 10.1111/MMI.12044

Experimental method

X-RAY DIFFRACTION (1.04 Å)