A silent regulatory gene cfaD' on region 1 of the CFA/I plasmid NTP 113 of enterotoxigenic Escherichia coli.
A DNA sequence, homologous to the cfaD gene of CFA/I region 2, was identified on CFA/I region 1. This sequence is designated cfaD'. It differs from the cfaD gene in containing two deletions and a stop codon. The cfaD' sequence therefore can only encode a truncated CfaD-like protein. The CfaD protein may be a DNA binding protein and functions as a positive regulator of CFA/I fimbriae expression. A regulatory function for the cfaD' is not likely since deletion of the cfaD' sequence does not affect production of CFA/I fimbriae in E. coli K-12 strains. That the cfaD' sequence is present on CFA/I wild-type plasmids isolated from CFA/I strains of different serotypes, obtained at various geographical locations, suggests, however, that this DNA region is not completely without a function.
Gaastra
W
W
Department of Bacteriology, Faculty of Veterinary Medicine, University of Utrecht, The Netherlands.
Jordi
B J
BJ
Mul
E M
EM
Hamers
A M
AM
McConnell
M M
MM
Willshaw
G A
GA
Smith
H R
HR
van der Zeijst
B A
BA
D000942:Antigens, Bacterial / Q000235:genetics*; D001426:Bacterial Proteins / Q000235:genetics*; D001483:Base Sequence; D004268:DNA-Binding Proteins; D004926:Escherichia coli; D029968:Escherichia coli Proteins; D036781:Fimbriae Proteins; D010861:Fimbriae, Bacterial; D005809:Genes, Regulator; D015336:Molecular Probe Techniques; D008969:Molecular Sequence Data; D016366:Open Reading Frames; D010957:Plasmids / Q000235:genetics*; D012045:Regulatory Sequences, Nucleic Acid / Q000235:genetics*; D012689:Sequence Homology, Nucleic Acid
D000942:Antigens, Bacterial; D001426:Bacterial Proteins; C069375:CfaD protein, E coli; D004268:DNA-Binding Proteins; D029968:Escherichia coli Proteins; C022924:colonization factor antigens; D036781:Fimbriae Proteins