title: CooC and CooD are required for assembly of CS1 pili.
abstract: Many strains of enterotoxigenic Escherichia coli (ETEC) isolated from patients with diarrhoeal disease exhibit CS1 pili on their surfaces. These appendages, which are thought to be important for colonization of the upper intestine, are composed largely of multiple identical protein subunits encoded by cooA. We have sequenced the DNA directly downstream of cooA and identified two open reading frames, cooC and cooD, transcribed in the same direction as cooB and cooA. Following cooD is DNA homologous to an insertion sequence, so cooB, A, C and D appear to encode all the information needed for E. coli K-12 to synthesize CS1 pili. Complementation analysis of mutants cloned in E. coli K-12 and constructed in an ETEC-derived strain indicates that cooC and cooD are not required for stability of the major CS1 pilin protein or for its transport to the periplasm, but, like cooB, both are needed for assembly of cooA into pili.
authors.affiliation: Department of Microbiology and Immunology, Emory University School of Medicine, Atlanta, Georgia 30322.
authors.forename: B J
authors.initials: BJ
authors.lastname: Froehlich
authors.forename: A
authors.initials: A
authors.lastname: Karakashian
authors.forename: L R
authors.initials: LR
authors.lastname: Melsen
authors.forename: J C
authors.initials: JC
authors.lastname: Wakefield
authors.forename: J R
authors.initials: JR
authors.lastname: Scott
mesh_terms: D000595:Amino Acid Sequence; D001425:Bacterial Outer Membrane Proteins / Q000096:biosynthesis*; D001426:Bacterial Proteins / Q000235:genetics* / Q000302:isolation & purification / Q000378:metabolism; D001483:Base Sequence; D004926:Escherichia coli / Q000235:genetics* / Q000254:growth & development / Q000648:ultrastructure; D029968:Escherichia coli Proteins; D036781:Fimbriae Proteins; D010861:Fimbriae, Bacterial / Q000378:metabolism* / Q000648:ultrastructure; D005798:Genes, Bacterial / Q000235:genetics*; D008565:Membrane Proteins; D008969:Molecular Sequence Data; D015183:Restriction Mapping; D017422:Sequence Analysis, DNA; D017384:Sequence Deletion; D017386:Sequence Homology, Amino Acid
chemical_list: D001425:Bacterial Outer Membrane Proteins; D001426:Bacterial Proteins; C088904:CooA protein, E coli; C088906:CooC protein, E coli; C088905:CooD protein, E coli; D029968:Escherichia coli Proteins; D008565:Membrane Proteins; D036781:Fimbriae Proteins