Wang, Liya
- Department of Animal Biosciences, Swedish University of Agricultural Sciences
Abstract
Mollicutes are wall-less bacteria and cause various diseases in humans, animals and plants. They have the smallest genomes with low G + C content and lack many genes of DNA, RNA and protein precursor biosynthesis. Nucleoside diphosphate kinase (NDK), a house-keeping enzyme that plays a critical role in the synthesis of nucleic acids precursors, i.e. NTPs and dNTPs, is absent in all the Mollicutes genomes sequenced to date. Therefore, it would be of interest to know how Mollicutes synthesize dNTPs/NTPs without NDK. To answer this question, nucleoside monophosphate kinases (NMPKs) from Ureaplasma were studied regarding their role in the synthesis of NTPs/dNTPs. In this work, Ureaplasma adenylate kinase, cytidylate kinase, uridylate kinase and thymidylate kinase were cloned and expressed in Escherichia coli. The recombinant enzymes were purified and characterized. These NMPKs are base specific, as indicated by their names, and capable of converting (d)NMPs directly to (d)NTPs. The catalytic rates of (d)NTPs and (d)NDP synthesis by these NMPKs were determined using tritium-labelled (d)NMPs, and the rates for (d)NDP synthesis, in general, were much higher (up to 100-fold) than that of (d)NTP. Equilibrium studies with adenylate kinase suggested that the rates of NTPs/dNTPs synthesis by NMPKs in vivo are probably regulated by the levels of (d)NMPs. These results strongly indicate that NMPKs could substitute the NDK function in vivo.
Keywords
Mollicutes; nucleotide biosynthesis; nucleoside diphosphate kinase; nucleoside monophosphate kinase; Ureaplasma
Published in
FEBS Journal
2007, volume: 274, number: 8, pages: 1983-1990
Publisher: BLACKWELL PUBLISHING
SLU Authors
UKÄ Subject classification
Animal and Dairy Science
Veterinary Science
Publication identifier
- DOI: https://doi.org/10.1111/j.1742-4658.2007.05742.x
Permanent link to this page (URI)
https://res.slu.se/id/publ/16745