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The Gene Encoding the Prepilin Peptidase Involved in Biosynthesis of Pilus Colonization Factor Antigen III (CFA/III) of Human Enterotoxigenic Escherichia coli
Author(s) -
Taniguchi Tooru,
Yasuda Yoko,
Tochikubo Kunio,
Yamamoto Koichiro,
Honda Takeshi
Publication year - 1999
Publication title -
microbiology and immunology
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.664
H-Index - 70
eISSN - 1348-0421
pISSN - 0385-5600
DOI - 10.1111/j.1348-0421.1999.tb01220.x
Subject(s) - pilus , biology , escherichia coli , colonization , microbiology and biotechnology , gene , antigen , genetics
The assembly of pilus colonization factor antigen III (CFA/III) of human enterotoxigenic Escherichia coli requires the processing of CFA/III major pilin (CofA) by a peptidase, likely another type IV pilus formation system. Western blot analysis of CofA reveals that CofA is produced initially as a 26.5‐kDa preform pilin (prepilin) and then processed to 20.5‐kDa mature pilin by a prepilin peptidase. This processing is essential for exportation of the CofA from the cytoplasm to the periplasm. In this experiment, the structural gene, cofP , encoding CFA/III prepilin peptidase which cleavages at the Gly‐30‐Met‐31 junction of CofA was identified, and the nucleotide sequence of the gene was determined. cofP consists of 819 bp encoding a 273‐amino acid protein with a relative molecular mass of 30,533 Da. CofP is predicted to be localized in the inner membrane based on its hydropathy index. The amino acid sequence of CofP shows a high degree of homology with other prepilin peptidases which play a role in the assembly of type IV pili in several gram‐negative bacteria.