Nucleotide sequences of the major subunits of F9 and F12 fimbriae of uropathogenic Escherichia coli

Abstract An Eco RV- Cla l fragment containing the gene encoding the F9 fimbrial subunit of the human uropathogenic Escherichia coli strain C1018 and a Pst l- Pst l fragment containing the F12 fimbrial subunit gene of the dog uropathogenic strain 1442 have been cloned and the nucleotide sequence of the fragments determined. The structural gene of the F9 fimbriae ( FniA ) codes for a protein of 165 amino acid residues with a signal peptide of 25 amino acids. The F12 fimbrial gene ( FtwA ) codes for a protein of 155 amino acids which is preceded by a single peptide of 21 amino acids. The amino acid sequences of the FniA and FtwA proteins deduced from the nucleotide sequence were compared with sequences of other known P-fimbrial subunit proteins. As expected, most differences between the various proteins were found in the hypervariable regions defined by van Die et al. (1987). The N-terminal sequence of the FtwA protein differs from the one published by Klemm et al . (1983). FtwA contains two deletions found in comparison to the other fimbrial subunits.