A rns-like regulatory gene for colonization factor antigen I (CFA/I) that controls expression of CFA/I pilin.
Colonization factor antigens (CFA) are needed for adherence of human enterotoxigenic Escherichia coli (ETEC) strains to their hosts. The CFA/II antigens, CS1 and CS2, which are found in some ETEC strains, require the plasmid-encoded gene rns for expression (J. Caron, L. M. Coffield, and J. R. Scott, Proc. Natl. Acad. Sci. USA 86:963-967, 1989). Other ETEC strains express CFA/I, whose synthesis and assembly require genes on two unlinked regions (regions 1 and 2) of a plasmid (G. A. Willshaw, H. R. Smith, and B. Rowe, FEMS Microbiol. Lett. 16:101-106, 1983). We report that CFA/I region 2 DNA can substitute for rns to cause expression of CS1 and CS2. The cfaR gene in region 2 is defined by a mutation abolishing both expression of CFA/I and complementation of a rns mutant for expression of CS1 or CS2. In a strain containing only region 1, complementation for expression of CFA/I by a plasmid containing rns+ is inefficient but is adequate to cause hemagglutination by the CFA/I adhesin.
Caron
J
J
Department of Microbiology and Immunology, Emory University Health Sciences Center, Atlanta, Georgia 30322.
Scott
J R
JR
D000942:Antigens, Bacterial / Q000032:analysis / Q000235:genetics*; D001425:Bacterial Outer Membrane Proteins / Q000235:genetics*; D036781:Fimbriae Proteins; D010861:Fimbriae, Bacterial / Q000502:physiology*; D015964:Gene Expression Regulation, Bacterial; D005798:Genes, Bacterial; D005809:Genes, Regulator; D005816:Genetic Complementation Test; D006384:Hemagglutination; D012689:Sequence Homology, Nucleic Acid
D000942:Antigens, Bacterial; D001425:Bacterial Outer Membrane Proteins; C022924:colonization factor antigens; D036781:Fimbriae Proteins