2btn: Difference between revisions

In many Gram-negative bacteria, including a number of pathogens such as, Pseudomonas aeruginosa and Erwinia carotovora, virulence factor production, and biofilm formation are linked to the quorum-sensing systems that use, diffusible N-acyl-L-homoserine lactones (AHLs) as intercellular messenger, molecules. A number of organisms also contain genes coding for lactonases, that hydrolyze AHLs into inactive products, thereby blocking the, quorum-sensing systems. Consequently, these enzymes attract intense, interest for the development of antiinfection therapies. However, the, catalytic mechanism of AHL-lactonase is poorly understood and subject to, controversy. We here report a 2.0-angstroms resolution structure of the, AHL-lactonase from Bacillus thuringiensis and a 1.7-angstroms crystal, structure of its complex with L-homoserine lactone. Despite limited, sequence similarity, the enzyme shows remarkable structural similarities, to glyoxalase II and RNase Z proteins, members of the, metallo-beta-lactamase superfamily. We present experimental evidence that, AHL-lactonase is a metalloenzyme containing two zinc ions involved in, catalysis, and we propose a catalytic mechanism for bacterial, metallo-AHL-lactonases.

2BTN is a [http://en.wikipedia.org/wiki/Single_protein Single protein] structure of sequence from [http://en.wikipedia.org/wiki/Bacillus_thuringiensis Bacillus thuringiensis] with ZN and GOL as [http://en.wikipedia.org/wiki/ligands ligands]. Structure known Active Site: AC1. Full crystallographic information is available from [http://ispc.weizmann.ac.il/oca-bin/ocashort?id=2BTN OCA].  

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