Premium
Genetics of capsule O‐acetylation in serogroup C, W‐135 and Y meningococci
Author(s) -
Claus Heike,
Borrow Ray,
Achtman Mark,
Morelli Giovanna,
Kantelberg Carmen,
Longworth Emma,
Frosch Matthias,
Vogel Ulrich
Publication year - 2004
Publication title -
molecular microbiology
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.857
H-Index - 247
eISSN - 1365-2958
pISSN - 0950-382X
DOI - 10.1046/j.1365-2958.2003.03819.x
Subject(s) - biology , acetylation , operon , gene , microbiology and biotechnology , sialic acid , neisseria meningitidis , peptide sequence , immunogenicity , homology (biology) , genetics , bacteria , escherichia coli , antigen
Summary Capsular polysaccharides of serogroup C, W‐135 and Y meningococci were previously reported to be O‐acetylated at the sialic acid residues. There is evidence that O‐acetylation affects the immunogenicity of polysaccharide vaccines. We identified genes indispensable for O‐acetylation of serogroup C, W‐135 and Y meningococci downstream of the capsule synthesis genes siaA–D . The genes were co‐transcribed with the sia operon as shown by reverse transcription polymerase chain reaction analysis. The putative capsular polysaccharide O‐acetyltransferases were designated OatC and OatWY. The protein OatWY of serogroups W‐135 and Y showed sequence homologies to members of the NodL–LacA–CysE family of bacterial acetyltransferases, whereas no sequence homology with any known protein in the different databases was found for the serogroup C protein OatC. In serogroup W‐135 and Y meningococci, several clonal lineages either lacked OatWY or OatWY was inactivated by insertion of IS 1301 . For serogroup C meningococci, we observed in vitro phase variation of O‐acetylation, which resulted from slipped‐strand mispairing in homopolymeric tracts. This finding explains the observation of naturally occurring de‐O‐acetylated serogroup C meningococci. Our report is the first description of sequences of sialic acid O‐acetyltransferase genes that have not been cloned from either other bacterial or mammalian organisms.