A FLAGELLAR SHEATH PROTEIN OF HELICOBACTER-PYLORI IS IDENTICAL TO HPAA, A PUTATIVE N-ACETYLNEURAMINYLLACTOSE-BINDING HEMAGGLUTININ, BUT IS NOT AN ADHESIN FOR AGS CELLS

The gene encoding a 29-kDa flagellar sheath protein was cloned and fou nd to be similar to hpaA, reported to encode an N-acetylneuraminyllact ose-binding fibrillar hemagglutinin (D. G. Evans, T. K. Karjalainen, D . J. Evans, Jr., D. Y. Graham, and C. H. Lee, J. Bacteriol. 175:674-68 3, 1943). The transcriptional start was mapped by primer extension fro m Helicobacter pylori mRNA, indicating an active consensus promoter at a location different from that suggested by Evans et al. Immunogold l abelling of the flagellar sheath with a monoclonal antibody to NpaA wa s demonstrated in four strains, contrary to previous reports of a surf ace (D. G. Evans, T. K. Karjalainen, D. J. Evans, Jr., D. Y. Graham, a nd C. H. Lee, J. Bacteriol. 175:674-683, 1993) or a cytoplasmic (P. W. O'Toole, L. Janzon, P. Doig, J. Huang, M. Kostrzynska, and T. J. Trus t, J. Bacteriol. 177:6049-6057, 1995) locale. Agglutination of erythro cytes and adherence: to AGS cells by a Delta hpaA mutant were no diffe rent from those of the parent strain, confirming a recent finding of O 'Toole et al.