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2avx
From Proteopedia
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'''solution structure of E coli SdiA1-171''' | '''solution structure of E coli SdiA1-171''' | ||
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[[Category: Wright, P E.]] | [[Category: Wright, P E.]] | ||
[[Category: Yao, Y.]] | [[Category: Yao, Y.]] | ||
| - | [[Category: | + | [[Category: Homoserine lactone]] |
| - | [[Category: | + | [[Category: Quorum sensing]] |
| - | + | ''Page seeded by [http://oca.weizmann.ac.il/oca OCA ] on Sat May 3 19:32:14 2008'' | |
| - | ''Page seeded by [http://oca.weizmann.ac.il/oca OCA ] on | + | |
Revision as of 16:32, 3 May 2008
solution structure of E coli SdiA1-171
Overview
The three-dimensional structure of a complex between the N-terminal domain of the quorum sensing protein SdiA of Escherichia coli and a candidate autoinducer N-octanoyl-L-homoserine lactone (C8-HSL) has been calculated in solution from NMR data. The SdiA-HSL system shows the "folding switch" behavior that has been seen for quorum-sensing factors produced by other bacterial species. In the presence of C8-HSL, a significant proportion of the SdiA protein is produced in a folded, soluble form in an E.coli expression system, whereas in the absence of acyl homoserine lactones, the protein is expressed into insoluble inclusion bodies. In the three-dimensional structure, the autoinducer molecule is sequestered in a deep pocket in the hydrophobic core, forming an integral part of the core packing of the folded SdiA. The NMR spectra of the complex show that the bound C8-HSL is conformationally heterogeneous, either due to motion within the pocket or to heterogeneity of the bound structure. The C8-HSL conformation is defined by NOEs to the protein only at the terminal methyl group of the octanoyl chain. Unlike other well-studied bacterial quorum sensing systems such as LuxR of Vibrio fischeri and TraR of Agrobacterium tumefaciens, there is no endogenous autoinducer for SdiA in E.coli: the E.coli genome does not contain a gene analogous to the LuxI and TraI autoinducer synthetases. We show that two other homoserine lactone derivatives are also capable of acting as a folding-switch autoinducers for SdiA. The observed structural heterogeneity of the bound C8-HSL in the complex, together with the variety of autoinducer-type molecules that can apparently act as folding switches in this system, are consistent with the postulated biological function of the SdiA protein as a detector of the presence of other species of bacteria.
About this Structure
2AVX is a Single protein structure of sequence from Escherichia coli. Full crystallographic information is available from OCA.
Reference
Structure of the Escherichia coli quorum sensing protein SdiA: activation of the folding switch by acyl homoserine lactones., Yao Y, Martinez-Yamout MA, Dickerson TJ, Brogan AP, Wright PE, Dyson HJ, J Mol Biol. 2006 Jan 13;355(2):262-73. Epub 2005 Nov 8. PMID:16307757 Page seeded by OCA on Sat May 3 19:32:14 2008
