Inorganic Polyphosphate/ATP-NAD kinase of Micrococcus flavus and Mycobacterium tuberculosis H37Rv

Biochem Biophys Res Commun. 2000 Sep 16;276(1):57-63. doi: 10.1006/bbrc.2000.3433.


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.

MeSH terms

  • Amino Acid Sequence
  • Bacterial Proteins / genetics
  • Bacterial Proteins / metabolism
  • Micrococcus / enzymology*
  • Molecular Sequence Data
  • Mycobacterium tuberculosis / enzymology*
  • Phosphotransferases (Alcohol Group Acceptor) / genetics*
  • Phosphotransferases (Alcohol Group Acceptor) / isolation & purification
  • Phosphotransferases (Alcohol Group Acceptor) / metabolism*
  • Polyphosphates


  • Bacterial Proteins
  • Polyphosphates
  • Phosphotransferases (Alcohol Group Acceptor)
  • NAD kinase