Statements in which the resource exists as a subject.
PredicateObject
rdf:type
lifeskim:mentions
pubmed:issue
8
pubmed:dateCreated
2007-4-16
pubmed:abstractText
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.
pubmed:language
eng
pubmed:journal
pubmed:citationSubset
IM
pubmed:chemical
pubmed:status
MEDLINE
pubmed:month
Apr
pubmed:issn
1742-464X
pubmed:author
pubmed:issnType
Print
pubmed:volume
274
pubmed:owner
NLM
pubmed:authorsComplete
Y
pubmed:pagination
1983-90
pubmed:meshHeading
pubmed:year
2007
pubmed:articleTitle
The role of Ureaplasma nucleoside monophosphate kinases in the synthesis of nucleoside triphosphates.
pubmed:affiliation
Department of Molecular Biosciences, Swedish University of Agricultural Sciences, The Biomedical Centre, Uppsala, Sweden. liya.wang@mbv.slu.se
pubmed:publicationType
Journal Article, Research Support, Non-U.S. Gov't