Sequence analysis of the outer membrane protein gene ompC of avian Escherichia coli

A pair of primers were designated based on the DNA sequence of the ompC gene of Escherichia coli K-12 in GenBank.With the special primers,ompC genes of E.coli O_(2),O_(78) and their fusion bivalent attenuated strain O_(2,78) were amplified by PCR.After sequenced,all of the three ompC genes contained (1 702) bp.Starting at nucleotide 491 and ending at nucleotide (1 582),an open reading frame(ORF) of (1 092) nt encodes the pro-OmpC protein consisting of 363 amino acid residuces.Hydrophobicity analysis suggested that the preceeding 21 amino acid constitute a typical signal sequence,suggesting that the mature form of OmpC protein is 342 amino acid long with the molecular weight (40 000).Analysis the nucleotide and amino acid sequence of the three ompC genes of avian Escherichia coli showed that the homology both were 100%.These results indicated that O_(2) and O_(78) have same outer membrane protein C antigen.