Display Settings:

Format

Send to:

Choose Destination
    J Mol Biol. 2007 Mar 2;366(4):1174-84. Epub 2006 Dec 16.

    Gene duplication of the eight-stranded beta-barrel OmpX produces a functional pore: a scenario for the evolution of transmembrane beta-barrels.

    Source

    Max Planck Institute for Developmental Biology, Department Protein Evolution, Spemannstr. 35, 72076 Tübingen, Germany.

    Abstract

    The repeating unit of outer membrane beta-barrels from Gram-negative bacteria is the beta-hairpin, and representatives of this protein family always have an even strand number between eight and 22. Two dominant structural forms have eight and 16 strands, respectively, suggesting gene duplication as a possible mechanism for their evolution. We duplicated the sequence of OmpX, an eight-stranded beta-barrel protein of known structure, and obtained a beta-barrel, designated Omp2X, which can fold in vitro and in vivo. Using single-channel conductance measurements and PEG exclusion assays, we found that Omp2X has a pore size similar to that of OmpC, a natural 16-stranded barrel. Fusions of the homologous proteins OmpX, OmpA and OmpW were able to fold in vitro in all combinations tested, revealing that the general propensity to form a beta-barrel is sufficient to evolve larger barrels by simple genetic events.

    PMID:
    17217961
    [PubMed - indexed for MEDLINE]

      Supplemental Content

      Icon for Elsevier Science

      Save items

      loading

      Recent activity

      Your browsing activity is empty.

      Activity recording is turned off.

      Turn recording back on

      See more...
      Write to the Help Desk