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A mannose-sensitive haemagglutinin (MSHA)-like pilus promotes attachment of Pseudoalteromonas tunicata cells to the surface of the green alga Ulva australis

Department of Chemistry and Biochemistry, University of California, San Diego, San Diego, California, United States
Microbiology (Impact Factor: 2.84). 11/2006; 152(Pt 10):2875-83. DOI: 10.1099/mic.0.29158-0
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ABSTRACT This study demonstrates that attachment of the marine bacterium Pseudoalteromonas tunicata to the cellulose-containing surface of the green alga Ulva australis is mediated by a mannose-sensitive haemagglutinin (MSHA-like) pilus. We have identified an MSHA pilus biogenesis gene locus in P. tunicata, termed msh/1/2JKLMNEGFBACDOPQ, which shows significant homology, with respect to its genetic characteristics and organization, to the MSHA pilus biogenesis gene locus of Vibrio cholerae. Electron microscopy studies revealed that P. tunicata wild-type cells express flexible pili peritrichously arranged on the cell surface. A P. tunicata mutant (SM5) with a transposon insertion in the mshJ region displayed a non-piliated phenotype. Using SM5, it has been demonstrated that the MSHA pilus promotes attachment of P. tunicata wild-type cells in polystyrene microtitre plates, as well as to microcrystalline cellulose and to the living surface of U. australis. P. tunicata also demonstrated increased pilus production in response to cellulose and its monomer constituent cellobiose. The MSHA pilus thus functions as a determinant of attachment in P. tunicata, and it is proposed that an understanding of surface sensing mechanisms displayed by P. tunicata will provide insight into specific ecological interactions that occur between this bacterium and higher marine organisms.

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Available from: Doralyn Dalisay, Jul 28, 2015
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    • "There were 17 genes in a cluster coding for a mannose-sensitive hemagglutinin (MSHA) biogenesis locus (Online Resource 5) in NW4327. The MSHA pili operon structure of NW4327 closely resembled that of P. tunicata (Dalisay et al. 2006) in which the MSHA pilus played a role in the attachment of the bacterium to abiotic and living surfaces (Dalisay et al. 2006). While NW4327 lacked the mshF gene found in P. tunicata, both strains contained the two mshI genes. "
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