Skip to main content

T7-induced DNA polymerase. Requirement for thioredoxin sulfhydryl groups.

Publication ,  Journal Article
Adler, S; Modrich, P
Published in: J Biol Chem
June 10, 1983

Bacteriophage T7-induced DNA polymerase is composed of a 1:1 complex of phage-induced gene 5 protein and Escherichia coli thioredoxin. Preparation of active subunits in the absence of sulfhydryl reagents indicates the reduced form of thioredoxin is sufficient for formation of the active holoenzyme. The oxidized form of thioredoxin, thioredoxin modified at one active site sulfhydryl by iodoacetate or methyl iodide, or thioredoxin modified at both active site sulfhydryls by N-ethylmaleimide, are all inactive, being defective in complex formation with gene 5 protein. Thioredoxin sulfhydryl groups present in native T7 DNA polymerase do not appear to be involved in an intersubunit disulfide bond; one and probably both sulfhydryls are available in the native holoenzyme for modification by N-ethylmaleimide. Furthermore, DNA substrates alter the reactivity of thioredoxin cysteines within the holoenzyme with respect to this reagent. Substrates for the single strand exonuclease enhance the reactivity of thioredoxin sulfhydryl groups while those for the polymerase or double strand exonuclease functions afford protection. It, therefore, seems likely that thioredoxin sulfhydryl groups are present in the reduced state within the native polymerase.

Duke Scholars

Published In

J Biol Chem

ISSN

0021-9258

Publication Date

June 10, 1983

Volume

258

Issue

11

Start / End Page

6956 / 6962

Location

United States

Related Subject Headings

  • Viral Proteins
  • Thioredoxins
  • T-Phages
  • Oxidation-Reduction
  • Kinetics
  • Escherichia coli
  • Enzyme Induction
  • DNA-Directed DNA Polymerase
  • DNA Replication
  • Biochemistry & Molecular Biology
 

Citation

APA
Chicago
ICMJE
MLA
NLM
Adler, S., & Modrich, P. (1983). T7-induced DNA polymerase. Requirement for thioredoxin sulfhydryl groups. J Biol Chem, 258(11), 6956–6962.
Adler, S., and P. Modrich. “T7-induced DNA polymerase. Requirement for thioredoxin sulfhydryl groups.J Biol Chem 258, no. 11 (June 10, 1983): 6956–62.
Adler S, Modrich P. T7-induced DNA polymerase. Requirement for thioredoxin sulfhydryl groups. J Biol Chem. 1983 Jun 10;258(11):6956–62.
Adler, S., and P. Modrich. “T7-induced DNA polymerase. Requirement for thioredoxin sulfhydryl groups.J Biol Chem, vol. 258, no. 11, June 1983, pp. 6956–62.
Adler S, Modrich P. T7-induced DNA polymerase. Requirement for thioredoxin sulfhydryl groups. J Biol Chem. 1983 Jun 10;258(11):6956–6962.

Published In

J Biol Chem

ISSN

0021-9258

Publication Date

June 10, 1983

Volume

258

Issue

11

Start / End Page

6956 / 6962

Location

United States

Related Subject Headings

  • Viral Proteins
  • Thioredoxins
  • T-Phages
  • Oxidation-Reduction
  • Kinetics
  • Escherichia coli
  • Enzyme Induction
  • DNA-Directed DNA Polymerase
  • DNA Replication
  • Biochemistry & Molecular Biology