A novel inorganic pyrophosphatase in Thermococcus onnurineus NA1.
The TON_0002 gene, which is in close proximity to the DNA polymerase locus in Thermococcus onnurineus NA1, has been shown to encode an inorganic pyrophosphatase. Its genomic position and function suggest a role for pyrophosphate hydrolysis during DNA polymerization. This is the first report of an inorganic pyrophosphatase belonging to the haloacid dehalogenase superfamily, in which unique residues in motif I and II have been replaced with Trp and Gly, respectively. The optimum pyrophosphatase activity of the recombinant enzyme occurred at pH 6, and it displayed an absolute dependence on divalent metal ions, among which Ni(2+) was the most efficient. The site-specific mutation of the Gly residue in motif II to Ala or Ser residue exhibited only a slight change in the enzymatic activity and the K(m) value.
Lee
Hyun Sook
HS
Marine Biotechnology Research Center, Korea Ocean Research and Development Institute, Ansan, Seoul, Korea.
Cho
Yona
Y
Kim
Yun-Jae
YJ
Lho
Tae-Ok
TO
Cha
Sun-Shin
SS
Lee
Jung-Hyun
JH
Kang
Sung Gyun
SG
D000595:Amino Acid Sequence; D019843:Archaeal Proteins / Q000737:chemistry* / Q000235:genetics / Q000378:metabolism; D004795:Enzyme Stability; D043564:Inorganic Pyrophosphatase / Q000737:chemistry* / Q000235:genetics / Q000378:metabolism; D007700:Kinetics; D008969:Molecular Sequence Data; D016415:Sequence Alignment; D019712:Thermococcus / Q000737:chemistry / Q000201:enzymology* / Q000235:genetics
D019843:Archaeal Proteins; D043564:Inorganic Pyrophosphatase