Cloned DNA fragment specifying major outer membrane protein a in Escherichia coli K-12

R C Gayda, A Markovitz
1978 Journal of Bacteriology  
Plasmid pMC44 is a recombinant plasmid that contains a 2-megadalton EcoRI fragment of Escherichia coli K-12 DNA joined to the cloning vehicle, pSC101. The polypeptides specified by plasmid pMC44 were identified and compared with those specified by pSC101 to determine those that are unique to pMC44. Three polypeptides specified by plasmid pMC44 were localized in the cell envelope fraction of minicells: a Sarkosyl-insoluble outer membrane polypeptide (designated M2), specified by the cloned
more » ... by the cloned 2-megadalton DNA fragment, and two Sarkosyl-soluble membrane polypeptides specified by the cloning plasmid pSC101. Bacteria containing plasmid pMC44 synthesized quantities of M2 approximately equal to the most abundant E. coli K-12 outer membrane protein. Evidence is presented that outer membrane polypeptide M2, specified by the recombinant plasmid pMC44, is the normal E. coli outer membrane protein designated protein by the recombinant plasmid pMC44 is identical to the normal E. coli outer membrane protein designated protein a by Lugtenberg et al. (23, 24) and 3b according to Schnaitman's nomenclature (3). MATERIALS AND METHODS Bacterial strains. All strains are derivatives of E. 369 on May 9, 2020 by guest
doi:10.1128/jb.136.1.369-380.1978 fatcat:fj6ch4ejffabjgmme6dxteelum