3vor

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Crystal Structure Analysis of the CofACrystal Structure Analysis of the CofA

Structural highlights

3vor is a 1 chain structure with sequence from Escherichia coli. Full crystallographic information is available from OCA. For a guided tour on the structure components use FirstGlance.
Method:X-ray diffraction, Resolution 0.9Å
Resources:FirstGlance, OCA, PDBe, RCSB, PDBsum, ProSAT

Function

Q59393_ECOLX

Publication Abstract from PubMed

CofA, a major pilin subunit of colonization factor antigen III (CFA/III), forms pili that mediate small-intestinal colonization by enterotoxigenic Escherichia coli (ETEC). In this study, the crystal structure of an N-terminally truncated version of CofA was determined by single-wavelength anomalous diffraction (SAD) phasing using five sulfurs in the protein. Given the counterbalance between anomalous signal strength and the undesired X-ray absorption of the solvent, diffraction data were collected at 1.5 A resolution using synchrotron radiation. These data were sufficient to elucidate the sulfur substructure at 1.38 A resolution. The low solvent content (29%) of the crystal necessitated that density modification be performed with an additional 0.9 A resolution data set to reduce the phase error caused by the small sulfur anomalous signal. The CofA structure showed the alphabeta-fold typical of type IVb pilins and showed high structural homology to that of TcpA for toxin-coregulated pili of Vibrio cholerae, including spatial distribution of key residues critical for pilin self-assembly. A pilus-filament model of CofA was built by computational docking and molecular-dynamics simulation using the previously reported filament model of TcpA as a structural template. This model revealed that the CofA filament surface was highly negatively charged and that a 23-residue-long loop between the alpha1 and alpha2 helices filled the gap between the pilin subunits. These characteristics could provide a unique binding epitope for the CFA/III pili of ETEC compared with other type IVb pili.

Structure of the CFA/III major pilin subunit CofA from human enterotoxigenic Escherichia coli determined at 0.90 A resolution by sulfur-SAD phasing.,Fukakusa S, Kawahara K, Nakamura S, Iwashita T, Baba S, Nishimura M, Kobayashi Y, Honda T, Iida T, Taniguchi T, Ohkubo T Acta Crystallogr D Biol Crystallogr. 2012 Oct;68(Pt 10):1418-29. Epub 2012 Sep, 13. PMID:22993096[1]

From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine.

See Also

References

  1. Fukakusa S, Kawahara K, Nakamura S, Iwashita T, Baba S, Nishimura M, Kobayashi Y, Honda T, Iida T, Taniguchi T, Ohkubo T. Structure of the CFA/III major pilin subunit CofA from human enterotoxigenic Escherichia coli determined at 0.90 A resolution by sulfur-SAD phasing. Acta Crystallogr D Biol Crystallogr. 2012 Oct;68(Pt 10):1418-29. Epub 2012 Sep, 13. PMID:22993096 doi:10.1107/S0907444912034464

3vor, resolution 0.90Å

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