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Structural basis for Zn2+-dependent intercellular adhesion in staphylococcal biofilms.

ABSTRACT: Staphylococcal bacteria, including Staphylococcus epidermidis and Staphylococcus aureus, cause chronic biofilm-related infections. The homologous proteins Aap and SasG mediate biofilm formation in S. epidermidis and S. aureus, respectively. The self-association of these proteins in the presence of Zn(2+) leads to the formation of extensive adhesive contacts between cells. This study reports the crystal structure of a Zn(2+) -bound construct from the self-associating region of Aap. Several unusual structural features include elongated ?-sheets that are solvent-exposed on both faces and the lack of a canonical hydrophobic core. Zn(2+)-dependent dimers are observed in three distinct crystal forms, formed via pleomorphic coordination of Zn(2+) in trans across the dimer interface. These structures illustrate how a long, flexible surface protein is able to form tight intercellular adhesion sites under adverse environmental conditions.

SUBMITTER: Conrady DG

PROVIDER: S-EPMC3549106 | biostudies-literature | 2013 Jan

REPOSITORIES: biostudies-literature

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Structural basis for Zn2+-dependent intercellular adhesion in staphylococcal biofilms.

Conrady Deborah G DG Wilson Jeffrey J JJ Herr Andrew B AB

Proceedings of the National Academy of Sciences of the United States of America 20121231 3

Staphylococcal bacteria, including Staphylococcus epidermidis and Staphylococcus aureus, cause chronic biofilm-related infections. The homologous proteins Aap and SasG mediate biofilm formation in S. epidermidis and S. aureus, respectively. The self-association of these proteins in the presence of Zn(2+) leads to the formation of extensive adhesive contacts between cells. This study reports the crystal structure of a Zn(2+) -bound construct from the self-associating region of Aap. Several unusua ...[more]

PMID: 23277549

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