Escherichia coli outer membrane protein K is a porin.
AUTOR(ES)
Sutcliffe, J
RESUMO
Protein K is an outer membrane protein found in pathogenic encapsulated strains of Escherichia coli. We present evidence here that protein K is structurally and functionally related to the E. coli K-12 porin proteins (OmpF, OmpC, and PhoE). Protein K was found to cross-react with antibody to OmpF protein and to share 8 out of 17 peptides in common with the OmpF protein. Strains that are OmpC porin- and OmpF porin- and contain protein K as their major outer membrane protein have increased rates of uptake of nutrients and a faster growth rate relative to the parental porin- strain. The protein K-containing strains are at least 1,000-fold more sensitive to colicins E2 and E3 than is the porin -deficient strain. These data suggest that protein K is a functional porin in E. coli. The porin function of protein K was also demonstrated in vitro, using black lipid membranes. Protein K increased the conductance in these membranes in discrete, uniform steps characteristic of channels with a size of about 2 nS.
ACESSO AO ARTIGO
http://www.pubmedcentral.nih.gov/articlerender.fcgi?artid=217905Documentos Relacionados
- The major outer membrane protein of Acidovorax delafieldii is an anion-selective porin.
- Purification of Legionella pneumophila major outer membrane protein and demonstration that it is a porin.
- The rare outer membrane protein, OmpL1, of pathogenic Leptospira species is a heat-modifiable porin.
- Plasmid-mediated sucrose metabolism in Escherichia coli: characterization of scrY, the structural gene for a phosphoenolpyruvate-dependent sucrose phosphotransferase system outer membrane porin.
- Regulation of outer membrane porin protein synthesis in Escherichia coli K-12: ompF regulates the expression of ompC.