title: The Legionella pneumophila hel locus encodes intracellularly induced homologs of heavy-metal ion transporters of Alcaligenes spp.
abstract: We continued characterization of the Legionella pneumophila hel locus. Mutagenesis and DNA sequencing identified three genes similar to the czc and cnr loci of Alcaligenes eutrophus and the ncc locus of Alcaligenes xylosoxidans. On the basis of their similarity to these loci, we designated the L. pneumophila genes helC, helB, and helA. Mutations in the hel genes led to reduced cytopathicity towards U937 cells, although the mutant strains did not appear defective in other assays of virulence. Transcription of the hel locus was induced by the intracellular environment but was not induced by any of a variety of in vitro stress conditions. The function of the hel gene products remains to be determined.
authors.affiliation: Department of Microbiology, University of Michigan Medical School, Ann Arbor 48109-0620, USA.
authors.forename: M S
authors.initials: MS
authors.lastname: McClain
authors.forename: M C
authors.initials: MC
authors.lastname: Hurley
authors.forename: J K
authors.initials: JK
authors.lastname: Brieland
authors.forename: N C
authors.initials: NC
authors.lastname: Engleberg
mesh_terms: D000421:Alcaligenes / Q000235:genetics* / Q000378:metabolism; D000595:Amino Acid Sequence; D001426:Bacterial Proteins / Q000235:genetics* / Q000378:metabolism; D001483:Base Sequence; D002352:Carrier Proteins / Q000235:genetics* / Q000378:metabolism; D002460:Cell Line; D002874:Chromosome Mapping; D004269:DNA, Bacterial / Q000235:genetics; D015964:Gene Expression Regulation, Bacterial; D005798:Genes, Bacterial; D006801:Humans; D017136:Ion Transport; D016952:Legionella pneumophila / Q000235:genetics* / Q000378:metabolism / Q000472:pathogenicity; D008670:Metals / Q000378:metabolism; D008969:Molecular Sequence Data; D009154:Mutation; D013045:Species Specificity; D014774:Virulence / Q000235:genetics
chemical_list: D001426:Bacterial Proteins; D002352:Carrier Proteins; D004269:DNA, Bacterial; C088933:Hel protein, Legionella pneumophila; D008670:Metals