title: The pnhA gene of Pasteurella multocida encodes a dinucleoside oligophosphate pyrophosphatase member of the Nudix hydrolase superfamily.
abstract: The pnhA gene of Pasteurella multocida encodes PnhA, which is a member of the Nudix hydrolase subfamily of dinucleoside oligophosphate pyrophosphatases. PnhA hydrolyzes diadenosine tetra-, penta-, and hexaphosphates with a preference for diadenosine pentaphosphate, from which it forms ATP and ADP. PnhA requires a divalent metal cation, Mg(2+) or Mn(2+), and prefers an alkaline pH of 8 for optimal activity. A P. multocida strain that lacked a functional pnhA gene, ACP13, was constructed to further characterize the function of PnhA. The cellular size of ACP13 was found to be 60% less than that of wild-type P. multocida, but the growth rate of ACP13 and its sensitivity to heat shock conditions were similar to those of the wild type, and the wild-type cell size was restored in the presence of a functional pnhA gene. Wild-type and ACP13 strains were tested for virulence by using the chicken embryo lethality model, and ACP13 was found to be up to 1,000-fold less virulent than the wild-type strain. This is the first study to use an animal model in assessing the virulence of a bacterial strain that lacked a dinucleoside oligophosphate pyrophosphatase and suggests that the pyrophosphatase PnhA, catalyzing the hydrolysis of diadenosine pentaphosphates, may also play a role in facilitating P. multocida pathogenicity in the host.
authors.affiliation: Department of Biological Sciences, University of Wisconsin-Parkside, P.O. Box 2000, Kenosha, WI 53144, USA.
authors.forename: Tonia
authors.initials: T
authors.lastname: Urick
authors.forename: Chien
authors.initials: C
authors.lastname: I-Chang
authors.forename: Ellen
authors.initials: E
authors.lastname: Arena
authors.forename: Wenlian
authors.initials: W
authors.lastname: Xu
authors.forename: Maurice J
authors.initials: MJ
authors.lastname: Bessman
authors.forename: Carmel G
authors.initials: CG
authors.lastname: Ruffolo
mesh_terms: D000818:Animals; D002642:Chick Embryo; D002645:Chickens; D015226:Dinucleoside Phosphates / Q000378:metabolism*; D008969:Molecular Sequence Data; D005810:Multigene Family; D016296:Mutagenesis; D016979:Pasteurella multocida / Q000201:enzymology* / Q000235:genetics* / Q000472:pathogenicity; D010641:Phenotype; D011755:Pyrophosphatases / Q000235:genetics* / Q000378:metabolism*; D014774:Virulence; D000096964:Nudix Hydrolases
chemical_list: D015226:Dinucleoside Phosphates; D011755:Pyrophosphatases; D000096964:Nudix Hydrolases