Identification and characterization of genes required for post-translational modification of Campylobacter coli VC167 flagellin.
Two genes have been identified in Campylobacter coli VC167 which are required for the biosynthesis of post-translational modifications on flagellin proteins. The ptmA gene encodes a protein of predicted M(r) 28,486 which shows significant homology to a family of alcohol dehydrogenases from a variety of bacteria. The ptmB gene encodes a protein of predicted M(r) 26,598 with significant homology to CMP-N-acetylneuraminic acid synthetase enzymes involved in sialic acid capsular biosynthesis in Neisseria meninigitidis and Escherichia coli K1. Site-specific mutation of either ptmA or ptmB caused loss of reactivity with antisera specific to the post-translational modifications and a change in the isoelectric focusing fingerprints relative to the parent strains. Mutation of ptmB, but not of ptmA, caused a change in apparent M(r) of the flagellin subunit in SDS-PAGE gels. The ptmA and ptmB genes are present in other strains of Campylobacter. In a rabbit model the ptmA mutant showed a reduced ability to elicit protection against subsequent challenge with heterologous strains of the same Lior serotype compared to the parental wild-type strain. This suggests that the surface-exposed post-translational modifications may play a significant role in the protective immune response.
Guerry
P
P
Enteric Diseases Program, Naval Medical Research Institute, Bethesda, Maryland 20889, USA. guerry_p@mail2.nmri.nnmc.navy.mil
Doig
P
P
Alm
R A
RA
Burr
D H
DH
Kinsella
N
N
Trust
T J
TJ
D000595:Amino Acid Sequence; D000818:Animals; D000918:Antibody Specificity; D001483:Base Sequence; D002167:Campylobacter / Q000235:genetics; D017000:Campylobacter coli / Q000235:genetics*; D002874:Chromosome Mapping; D003001:Cloning, Molecular; D003569:Cytidine Monophosphate N-Acetylneuraminic Acid; D004269:DNA, Bacterial / Q000235:genetics; D005408:Flagellin / Q000378:metabolism*; D005798:Genes, Bacterial / Q000235:genetics*; D008969:Molecular Sequence Data; D009154:Mutation; D011499:Protein Processing, Post-Translational; D011817:Rabbits; D017421:Sequence Analysis; D017386:Sequence Homology, Amino Acid
D004269:DNA, Bacterial; D005408:Flagellin; D003569:Cytidine Monophosphate N-Acetylneuraminic Acid