J. Bacteriol., 04 1996, 1777-1781, Vol 178, No. 7
S Shankar, S Kamath and AM Chakrabarty
Nucleoside diphosphate kinase (EC 2.7.4.6) (Ndk) is a ubiquitous enzyme
functioning in the intracellular distribution of terminal phosphate bond
energy among the various nucleotides used in synthetic and regulatory
functions in cells. We have previously reported that in Pseudomonas
aeruginosa, this important enzyme is transcriptionally regulated by the
gene algR2 and posttranslationally regulated by a phosphoprotein
phosphatase for the phosphorylated form of Ndk. We report here that an
intracellular protease cleaves the 16-kDa form of Ndk to a 12-kDa form that
undergoes autophosphorylation with an efficiency almost identical to that
of the 16-kDa form. The 12-kDa form was found to be predominantly
associated with the P. aeruginosa cell membrane fraction, whereas the
16-kDa form was predominantly cytoplasmic. In the membrane-associated
state, the 12-kDa form of Ndk was found to synthesize GTP in preference to
other nucleoside triphosphates. The specificity toward GTP synthesis could
be abolished by the addition of Tween 20 or Triton X-100. The activity
itself could be abolished by the addition of anti-Ndk antibody to the assay
mixture. The formation of the 12-kDa form of Ndk and its association with
the cell membrane were found to be related to the growth stage of P.
aeruginosa, with less than 1% of the 12-kDa Ndk detectable in the membrane
fraction at early log phase in comparison with the levels present at late
stationary phase.
Copyright © 1996, American Society for Microbiology
Two forms of the nucleoside diphosphate kinase of Pseudomonas aeruginosa 8830: altered specificity of nucleoside triphosphate synthesis by the cell membrane-associated form of the truncated enzyme
Department of Microbiology and Immunology, University of Illinois College of Medicine, Chicago , Illinois 60612, USA.
This article has been cited by other articles:
Copyright © 2009 by the American Society for Microbiology. For an alternate route to Journals.ASM.org, visit: http://intl-journals.asm.org | More Info»