Molecular Characteristics of OmpF-Like Porins from Pathogenic Yersinia

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K. V. Guzev^*, M. P. Isaeva, O. D. Novikova, T. F. Solov'eva, and V. A. Rasskazov

Pacific Institute of Bioorganic Chemistry, Far-Eastern Branch, Russian Academy of Sciences, pr. 100 Let Vladivostoku 159, 690022 Vladivostok, Russia; fax: 7 (4232) 314-050; E-mail: kotok@piboc.dvo.ru

^* To whom correspondence should be addressed.

Received September 3, 2004; Revision received November 25, 2004

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Nonspecific pore-forming proteins (porins) are the major proteins of the outer membrane of Gram-negative bacteria responsible for diffusion of low-molecular-weight compounds. Nucleotide sequences of the OmpF-like porins from the pathogenic bacteria Yersinia pseudotuberculosis (YPS) and Yersinia enterocolitica (YE) were cloned and determined. Values of molecular weights (MW) and isoelectric points (IEP) calculated for these proteins (for OmpF-YPS: MW 37.7 kD, IEP 4.45; for OmpF-YE: MW 39.5 kD, IEP 4.34) are in good agreement with experimental data. The OmpF-like Yersinia porins are highly homologous to each other (83-92%) and also to the OmpF protein from Serratia marcescens (70%); the homology to the OmpF porin from E. coli is significantly lower (52-58%). Multiple alignment of the amino acid sequences of mature OmpF proteins provided the distribution of conservative amino acid residues typical for porins. Moreover, the OmpF-like porins from Yersinia are characterized by the presence of extended regions with high and low homologies, which coincide with the transmembrane domains and “external” loops, respectively, of the topological model of the OmpF porin from E. coli. By predictive methods, the secondary structure of the OmpF-like porins from Yersinia was obtained. This structure is represented by 16 beta-strands connected by short “periplasmic” and longer “external” loops with unordered structure.

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KEY WORDS: porin, OmpF, Yersinia pseudotuberculosis, Yersinia enterocolitica

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