J Michael Sauder - A structural genomics approach to the study of quorum sensing: crystal structures of three LuxS orthologs

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  Publication Details (including relevant citation   information):

  Structure (2001) 9: 527-537.

  Lewis HA, Furlong EB, Laubert B, Eroshkina GA, Batiyenko Y, Adams   JM, Bergseid MG, Marsh CD, Peat TS, Sanderson WE, Sauder JM,   Buchanan SG


  BACKGROUND: Quorum sensing is the mechanism by which bacteria   control  gene expression in response to cell density. Two   major quorum-sensing  systems have been identified, system 1   and system 2, each with a  characteristic signaling molecule   (autoinducer-1, or AI-1, in the case  of system 1, and AI-2   in system 2). The luxS gene is required for the  AI-2 system   of quorum sensing. LuxS and AI-2 have been described in   both  Gram-negative and Gram-positive bacterial species and   have been shown  to be involved in the expression of   virulence genes in several  pathogens. RESULTS: The   structure of the LuxS protein from three  different   bacterial species with resolutions ranging from 1.8 A to 2.4   A  has been solved using an X-ray crystallographic   structural genomics  approach. The structure of LuxS   reported here is seen to have a new  alpha-beta fold. In all   structures, an equivalent homodimer is observed.  A metal   ion identified as zinc was seen bound to a Cys-His-His   triad.  Methionine was found bound to the protein near the   metal and at the  dimer interface. CONCLUSIONS: These   structures provide support for a  hypothesis that explains   the in vivo action of LuxS. Specifically,  acting as a   homodimer, the protein binds a methionine analog,    S-ribosylhomocysteine (SRH). The zinc atom is in position to   cleave the  ribose ring in a step along the synthesis   pathway of AI-2.

  Address (URL): http://www.cell.com/structure/retrieve/pii/S096921260100613X