Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: EC:2.7.7.7 (DNA polymerase)
 17,007 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Thioredoxin is a small (Mr 12,000) ubiquitous redox protein with the conserved active site structure: -Trp-Cys-Gly-Pro-Cys-. The oxidized form (Trx-S2) contains a disulfide bridge which is reduced by NADPH and thioredoxin reductase; the reduced form [Trx(SH)2] is a powerful protein disulfide oxidoreductase. Thioredoxins have been characterized in a wide variety of prokaryotic cells, and generally show about 50% amino acid homology to Escherichia coli thioredoxin with a known three-dimensional structure. In vitro Trx-(SH)2 serves as a hydrogen donor for ribonucleotide reductase, an essential enzyme in DNA synthesis, and for enzymes reducing sulfate or methionine sulfoxide. E. coli Trx-(SH)2 is essential for phage T7 DNA replication as a subunit of T7 DNA polymerase and also for assembly of the filamentous phages f1 and M13 perhaps through its localization at the cellular plasma membrane. Some photosynthetic organisms reduce Trx-S2 by light and ferredoxin; Trx-(SH)2 is used as a disulfide reductase to regulate the activity of enzymes by thiol redox control. Thioredoxin-negative mutants (trxA) of E. coli are viable making the precise cellular physiological functions of thioredoxin unknown. Another small E. coli protein, glutaredoxin, enables GSH to be hydrogen donor for ribonucleotide reductase or PAPS reductase. Further experiments with molecular genetic techniques are required to define the relative roles of the thioredoxin and glutaredoxin systems in intracellular redox reactions.
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PMID:Thioredoxin and related proteins in procaryotes. 315 90

We reported previously that a novel dipeptide alcohol, L-homoserylaminoethanol (Hse-Gly-ol), is a selective inhibitor of eukaryotic DNA polymerase epsilon (pol epsilon). The discovery suggests that the dipeptide structure could be a chemical frame for a DNA polymerase inhibitor. Therefore, we chemically synthesized 14 different species of dipeptide alcohols and their derivatives, and tested this inhibitory capability. The mercapto group in the dipeptide alcohol was found to be important, and compound 4 (L-cysteinylaminoethanol, Cys-Gly-ol) was the strongest pol alpha inhibitor. Compound 4 did not influence the activities of other replicative DNA polymerases such as delta and epsilon, and had no effect on the activities of prokaryotic DNA polymerases, nor DNA metabolic enzymes such as human immunodeficiency virus type-1 reverse transcriptase, T7 RNA polymerase and bovine deoxyribonuclease I. The inhibitory effect of compound 4 on pol alpha was dose-dependent, and 50% inhibition was observed at a concentration of 14.8 microM. Compound 4-induced inhibition of pol alpha activity was non-competitive with both the DNA template-primer and the nucleotide substrate. The relationships between the structures of dipeptide alcohol and the inhibition of eukaryotic DNA polymerases are discussed.
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PMID:Inhibitory effect of dipeptide alcohol derivatives containing mercapto group on eukaryotic DNA polymerase alpha. 1614