Topoisomerase I of Helicobacter pylori: Juxtaposition with a flagellin gene (flaB) and functional requirement of a fourth zinc finger motif

Sebastian Suerbaum, Tanja Brauer-Steppkes, Agnès Labigne, Béatrice Cameron, Karl Drlica

Research output: Contribution to journalArticlepeer-review

29 Scopus citations

Abstract

Cloning and nucleotide sequence analysis showed that in Helicobacter pylori the gene encoding topoisomerase I (topA) lies about 170 nucleotides upstream from flaB, a gene encoding one of the two flagellin proteins that is required for virulence. The topA and flaB genes are divergently transcribed. The orientation and spatial relationship between flaB and topA are remarkably conserved among strains of a bacterium in which genomic rearrangements are common. The deduced amino acid sequence of topoisomerase I revealed four zinc finger motifs, one more than has been reported previously for the Escherichia coli homologue. The additional motif, which is near the C-terminus of the protein, appears to be essential for function since mutations in that region are lethal. These data show that TopA proteins can be divided into several classes on the basis of zinc finger motifs and raise the interesting possibility that the H. pylori enzyme has local topological effects focussed on a flagellin gene.

Original languageEnglish (US)
Pages (from-to)151-161
Number of pages11
JournalGene
Volume210
Issue number1
DOIs
StatePublished - Mar 27 1998

All Science Journal Classification (ASJC) codes

  • Genetics

Keywords

  • DNA supercoiling
  • Flagellin
  • Virulence
  • flaB
  • topA

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