Structure and function of an essential component of the outer membrane protein assembly machine.

Department of Chemistry and Chemical Biology, Harvard University, Cambridge, MA 02138, USA.
Science (Impact Factor: 31.48). 09/2007; 317(5840):961-4. DOI: 10.1126/science.1143993
Source: PubMed

ABSTRACT Integral beta-barrel proteins are found in the outer membranes of mitochondria, chloroplasts, and Gram-negative bacteria. The machine that assembles these proteins contains an integral membrane protein, called YaeT in Escherichia coli, which has one or more polypeptide transport-associated (POTRA) domains. The crystal structure of a periplasmic fragment of YaeT reveals the POTRA domain fold and suggests a model for how POTRA domains can bind different peptide sequences, as required for a machine that handles numerous beta-barrel protein precursors. Analysis of POTRA domain deletions shows which are essential and provides a view of the spatial organization of this assembly machine.

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