Assembly of CS1 Pili: the Role of Specific Residues of the Major Pilin, CooA

• DOI: 10.1128/jb.188.1.231-239.2006
• Publication Date: 2005-12-13T22:38:09Z
• Authors: Angela M. Starks; Barbara J. Froehlich; Tamara N. Jones; June R. Scott
• Keywords: Pilin; Fimbriae Proteins; Alanine

CS1 pili are important virulence factors of enterotoxigenic Escherichia coli strains associated with human diarrheal disease. They the prototype for a family that share extensive sequence similarity among their structural and assembly proteins. Only four linked genes, cooB, cooA, cooC, cooD, required to produce in E. K-12. To identify amino acids function major pilin CooA, we used alanine substitution mutagenesis targeting conserved residues N C termini protein. test function, examined cooA mutants ability agglutinate bovine erythrocytes. Each hemagglutination-negative (HA(-)) mutant was its pathway defect. CooA has been shown be degraded absence CooB (K. Voegele, H. Sakellaris, J. R. Scott, Proc. Natl. Acad. Sci. USA 94:13257-13261, 1997). We found several HA(-) produced no detectable suggesting recognition by is mediated both CooA. In addition, some C-terminal motif "AGxYxG(x(6))T," which all subunits this pilus family, had effect on formation. However, alternating hydrophobic within prevented from interacting CooD, serves as tip adhesin nucleation protein Thus, it appears some, but not all, play critical role intermolecular interactions other anticipate results obtained here will help develop an understanding members pathogens.