Inorganic Polyphosphate/ATP-NAD kinase of Micrococcus flavus and Mycobacterium tuberculosis H37Rv.
An enzyme with both inorganic polyphosphate [poly(P)]- and ATP-dependent NAD kinase activities was isolated from Micrococcus flavus. The enzyme was a dimer consisting of 34 kDa subunits, and was named poly(P)/ATP-NAD kinase. Internal amino acid sequences of the enzyme showed homologies with some function-unknown proteins released on the GenBank database. Among such proteins, hypothetical Rv1695 protein (Accession No. Z98268-16), which was encoded by a gene named "Rv1695" on genomic DNA of Mycobacterium tuberculosis H37Rv, was proposed to be poly(P)-dependent NAD kinase. By cloning and expression in Escherichia coli, Rv1695 was shown to encode poly(P)/ATP-NAD kinase and named ppnk. The ppnk product, recombinant-poly(P)/ATP-NAD kinase (Ppnk) was purified and characterized. The enzyme was a tetramaer consisting of 35 kDa subunits when expressed in E. coli. Poly(P)/ATP-NAD kinases of M. flavus and Ppnk of M. tuberculosis H37Rv specifically and completely phosphorylated NAD by utilizing commercially available poly(P)s and nucleoside triphosphates as phosphoryl donors.
Kawai
S
S
Research Institute for Food Science, Kyoto University, Uji, Kyoto, 611-0011, Japan. kawai@food2.food.kyoto-u.ac.jp
Mori
S
S
Mukai
T
T
Suzuki
S
S
Yamada
T
T
Hashimoto
W
W
Murata
K
K
D000595:Amino Acid Sequence; D001426:Bacterial Proteins / Q000235:genetics / Q000378:metabolism; D008837:Micrococcus / Q000201:enzymology*; D008969:Molecular Sequence Data; D009169:Mycobacterium tuberculosis / Q000201:enzymology*; D017853:Phosphotransferases (Alcohol Group Acceptor) / Q000235:genetics* / Q000302:isolation & purification / Q000378:metabolism*; D011122:Polyphosphates
D001426:Bacterial Proteins; D011122:Polyphosphates; D017853:Phosphotransferases (Alcohol Group Acceptor); C021844:NAD kinase