HOME HELP FEEDBACK SUBSCRIPTIONS ARCHIVE SEARCH TABLE OF CONTENTS		QUICK SEARCH:   [advanced] Author: Keyword(s): Year:  Vol:  Page:

This Article Full Text Full Text (PDF) Alert me when this article is cited Alert me if a correction is posted Citation Map Services Email this article to a friend Similar articles in this journal Similar articles in PubMed Alert me to new issues of the journal Download to citation manager Citing Articles Citing Articles via HighWire Citing Articles via CrossRef Citing Articles via Google Scholar Google Scholar Articles by Meinersmann, R. J. Articles by Hiett, K. L. Search for Related Content PubMed PubMed Citation Articles by Meinersmann, R. J. Articles by Hiett, K. L. Agricola Articles by Meinersmann, R. J. Articles by Hiett, K. L.

Concerted evolution of duplicate fla genes in Campylobacter

USDA Agricultural Research Service, Russell Research Center, PO Box 5677, Athens, GA 30604-5677, USA¹

Author for correspondence: Richard Meinersmann. Tel: +1 706 546 3236. Fax: +1 706 546 3633. e-mail: rmeiners{at}asrr.arsusda.gov

Campylobacters have two similar copies (flaA and flaB) of their flagellin gene. It has been hypothesized that the two copies can serve for antigenic phase variation. Analysis of polymorphisms within aligned multiple DNA sequences of the Campylobacter flagellin genes revealed high pairwise homoplasy indexes between flaB/flaB pairs that were not observed between any flaA/flaA pairings or flaA/flaB pairings. Thus it seems there are constraints on the sequence of flaB that distinguish it from flaA. Nevertheless, segments of the two genes that are highly variable between strains are conserved between the flaA and flaB copies of the genes within a strain. The patterns of synonymous and non-synonymous differences suggest that one segment of the flagellin sequence is under selective pressure at the amino acid sequence level. Another segment of the protein is maintained within a strain by conversion or recombination. Comparisons of strict consensus amino acid sequences did not reveal any motifs that are uniquely FlaA or FlaB, but there are differences between FlaA and FlaB in those amino acids available for post-translational modification. The observed pattern of concerted evolution of portions of a structural gene is an unusual finding in bacteria and should be searched for with other duplicated genes. Concerted evolution was unexpected for genes involved in phase variation since it minimizes the antigenic repertoire that can be expressed by a single clone in the face of the host immune response.

Keywords: Campylobacter, flagellin, concerted evolution, DNA multiple-sequence analyses

This article has been cited by other articles:

				R. J. Meinersmann, R. W. Phillips, K. L. Hiett, and P. Fedorka-Cray Differentiation of Campylobacter Populations as Demonstrated by Flagellin Short Variable Region Sequences Appl. Envir. Microbiol., October 1, 2005; 71(10): 6368 - 6374. [Abstract] [Full Text] [PDF]

				G. Santoyo, J. M. Martinez-Salazar, C. Rodriguez, and D. Romero Gene Conversion Tracts Associated with Crossovers in Rhizobium etli J. Bacteriol., June 15, 2005; 187(12): 4116 - 4126. [Abstract] [Full Text] [PDF]

				A. J. H. Leatherbarrow, C. A. Hart, R. Kemp, N. J. Williams, A. Ridley, M. Sharma, P. J. Diggle, E. J. Wright, J. Sutherst, and N. P. French Genotypic and Antibiotic Susceptibility Characteristics of a Campylobacter coli Population Isolated from Dairy Farmland in the United Kingdom Appl. Envir. Microbiol., February 1, 2004; 70(2): 822 - 830. [Abstract] [Full Text] [PDF]

				Z. Zhang, T. Cavalier-Smith, and B. R. Green Evolution of Dinoflagellate Unigenic Minicircles and the Partially Concerted Divergence of Their Putative Replicon Origins Mol. Biol. Evol., April 1, 2002; 19(4): 489 - 500. [Abstract] [Full Text] [PDF]