title: Functional analysis of the multi-copper oxidase from Legionella pneumophila.
abstract: Multicopper oxidases have been described to have functions in copper tolerance, manganese oxidation, and iron oxidation in a range of bacteria. The putative cytoplasmic membrane multicopper oxidase from Legionella pneumophila was investigated. The mcoL gene was found to be critical for aerobic extracellular growth under either iron-limiting conditions or in the presence of ferrous Fe(II) iron, as a sole source of this essential metal. The mcoL mutants showed minor growth defects when grown in the presence of Fe(III) as the iron source. In contrast, intracellular growth and survival was not affected by the absence of the mcoL gene regardless of available iron concentration. The evidence presented here could indicate a possible role for mcoL in prevention of the toxic effects of ferrous iron during aerobic conditions. However, a function in high-affinity acquisition of iron could also be possible given the inability of the McoL mutants to grow aerobically under iron-limiting conditions.
authors.affiliation: Centre for Metals in Biology and School of Molecular and Microbial Sciences, University of Queensland, St Lucia, QLD 4072, Australia.
authors.forename: Wilhelmina M
authors.initials: WM
authors.lastname: Huston
authors.forename: Jennifer
authors.initials: J
authors.lastname: Naylor
authors.forename: Nicholas P
authors.initials: NP
authors.lastname: Cianciotto
authors.forename: Michael P
authors.initials: MP
authors.lastname: Jennings
authors.forename: Alastair G
authors.initials: AG
authors.lastname: McEwan
mesh_terms: D000332:Aerobiosis; D000818:Animals; D001483:Base Sequence; D002462:Cell Membrane / Q000201:enzymology; D019327:Copper Sulfate / Q000378:metabolism; D004269:DNA, Bacterial / Q000032:analysis; D011756:Diphosphates / Q000378:metabolism; D052978:Disk Diffusion Antimicrobial Tests; D005296:Ferrous Compounds / Q000378:metabolism; D005798:Genes, Bacterial; D006249:Hartmannella / Q000382:microbiology; D006801:Humans; D007501:Iron / Q000378:metabolism; D042845:Laccase / Q000378:metabolism; D016952:Legionella pneumophila / Q000201:enzymology* / Q000235:genetics* / Q000472:pathogenicity; D007877:Legionnaires' Disease / Q000382:microbiology; D008969:Molecular Sequence Data; D016254:Mutagenesis, Insertional; D010088:Oxidoreductases / Q000235:genetics* / Q000378:metabolism*; D017422:Sequence Analysis, DNA; D020298:U937 Cells
chemical_list: D004269:DNA, Bacterial; D011756:Diphosphates; D005296:Ferrous Compounds; C020748:ferrous sulfate; D007501:Iron; D010088:Oxidoreductases; D042845:Laccase; C024748:copper oxidase; D019327:Copper Sulfate; C049051:ferric pyrophosphate