Statements in which the resource exists as a subject.
PredicateObject
rdf:type
lifeskim:mentions
pubmed:issue
29
pubmed:dateCreated
1997-8-18
pubmed:abstractText
Ribonucleotides are converted to deoxyribonucleotides by ribonucleotide reductases. Either thioredoxin or glutaredoxin is a required electron donor for class I and II enzymes. Glutaredoxins are reduced by glutathione, thioredoxins by thioredoxin reductase. Recently, a glutaredoxin-like protein, NrdH, was isolated as the functional electron donor for a NrdEF ribonucleotide reductase, a class Ib enzyme, from Lactococcus lactis. The absence of glutathione in this bacterium raised the question of the identity of the intracellular reductant for NrdH. Homologues of NrdH are present in the genomes of Escherichia coli and Salmonella typhimurium, upstream of the genes for the poorly transcribed nrdEF, separated from it by an open reading frame (nrdI) coding for a protein of unknown function. Overexpression of E. coli NrdH protein shows that it is a functional hydrogen donor with higher specificity for the class Ib (NrdEF) than for the class Ia (NrdAB) ribonucleotide reductase. Furthermore, this glutaredoxin-like enzyme is reduced by thioredoxin reductase and not by glutathione. We suggest that several uncharacterized glutaredoxin-like proteins present in the genomes of organisms lacking GSH, including archae, will also react with thioredoxin reductase and be related to the ancestors from which the GSH-dependent glutaredoxins have evolved by the acquisition of a GSH-binding site. We also show that NrdI, encoded by all nrdEF operons, has a stimulatory effect on ribonucleotide reduction.
pubmed:language
eng
pubmed:journal
pubmed:citationSubset
IM
pubmed:chemical
pubmed:status
MEDLINE
pubmed:month
Jul
pubmed:issn
0021-9258
pubmed:author
pubmed:issnType
Print
pubmed:day
18
pubmed:volume
272
pubmed:owner
NLM
pubmed:authorsComplete
Y
pubmed:pagination
18044-50
pubmed:dateRevised
2007-11-15
pubmed:meshHeading
pubmed-meshheading:9218434-Amino Acid Sequence, pubmed-meshheading:9218434-Bacterial Proteins, pubmed-meshheading:9218434-Cloning, Molecular, pubmed-meshheading:9218434-DNA Primers, pubmed-meshheading:9218434-Escherichia coli, pubmed-meshheading:9218434-Escherichia coli Proteins, pubmed-meshheading:9218434-Glutaredoxins, pubmed-meshheading:9218434-Kinetics, pubmed-meshheading:9218434-Molecular Sequence Data, pubmed-meshheading:9218434-Oxidoreductases, pubmed-meshheading:9218434-Phylogeny, pubmed-meshheading:9218434-Polymerase Chain Reaction, pubmed-meshheading:9218434-Proteins, pubmed-meshheading:9218434-Recombinant Proteins, pubmed-meshheading:9218434-Ribonucleotide Reductases, pubmed-meshheading:9218434-Salmonella typhimurium, pubmed-meshheading:9218434-Sequence Alignment, pubmed-meshheading:9218434-Sequence Homology, Amino Acid, pubmed-meshheading:9218434-Thioredoxins
pubmed:year
1997
pubmed:articleTitle
Characterization of Escherichia coli NrdH. A glutaredoxin-like protein with a thioredoxin-like activity profile.
pubmed:affiliation
Medical Nobel Institute for Biochemistry, Department of Medical Biochemistry and Biophysics, Karolinska Institute, S-171 77 Stockholm, Sweden.
pubmed:publicationType
Journal Article, Comparative Study, Research Support, Non-U.S. Gov't