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1ro5
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(New page: 200px<br /><applet load="1ro5" size="450" color="white" frame="true" align="right" spinBox="true" caption="1ro5, resolution 2.30Å" /> '''Crystal Structure of...)
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Revision as of 23:37, 20 November 2007
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Crystal Structure of the AHL Synthase LasI
Overview
The LasI/LasR quorum-sensing system plays a pivotal role in virulence gene, regulation of the opportunistic human pathogen, Pseudomonas aeruginosa., Here we report the crystal structure of the acyl-homoserine lactone (AHL), synthase LasI that produces 3-oxo-C12-AHL from the substrates, 3-oxo-C12-acyl-carrier protein (acyl-ACP) and S-adenosyl-L-methionine. The, LasI six-stranded beta sheet platform, buttressed by three alpha helices, forms a V-shaped substrate-binding cleft that leads to a tunnel passing, through the enzyme that can accommodate the acyl-chain of acyl-ACP. This, tunnel places no apparent restriction on acyl-chain length, in contrast to, a restrictive hydrophobic pocket seen in the AHL-synthase EsaI., Interactions of essential conserved N-terminal residues, Arg23, Phe27 and, Trp33, suggest that the N-terminus forms an enclosed substrate-binding, pocket for S-adenosyl-L-methionine. Analysis of AHL-synthase surface, residues identified a binding site for acyl-ACP, a role that was supported, by in vivo reporter assay analysis of the mutated residues, including, Arg154 and Lys150. This structure and the novel explanation of, AHL-synthase acyl-chain-length selectivity promise to guide the design of, Pseudomonas aeruginosa-specific quorum-sensing inhibitors as antibacterial, agents.
About this Structure
1RO5 is a Single protein structure of sequence from Pseudomonas aeruginosa with SO4 and ZN as ligands. Full crystallographic information is available from OCA.
Reference
Structure of the Pseudomonas aeruginosa acyl-homoserinelactone synthase LasI., Gould TA, Schweizer HP, Churchill ME, Mol Microbiol. 2004 Aug;53(4):1135-46. PMID:15306017
Page seeded by OCA on Wed Nov 21 01:44:50 2007
