Complexes of Rep protein with ATP and DNA as a basis for helicase action.

Important note: Information in this article was accurate in 1981. The state of the art may have changed since the publication date.

Complexes of Rep protein with ATP and DNA as a basis for helicase action.

J Biol Chem. 1981 May 25;256(10):5287-93. Unique Identifier : AIDSLINE MED/81191941
Arai N; Arai K; Kornberg A

Abstract: The rep protein of Escherichia coli, a helicase that unwinds duplex DNA at a replication fork (Kornberg, A., Scott, J. F., and Bertsch, L. L. (1978) J. Biol. Chem. 253, 3298-3304), forms binary complexes with ATP and with DNA, and ternary complexes with both. ATP (or dATP) is bound at a single site with a dissociation constant (KD) near 10(-7) M. Other ribonucleoside triphosphates and deoxyribonucleoside triphosphates compete for the same site with far lower affinities. The protein forms a binary complex with single-stranded DNA and with duplex DNA, each at distinctive sites. Binding to single-stranded DNA covers a stretch of approximately 20 nucleotides, destabilizes secondary structure, and facilitates reannealing of complementary single strands. Ternary complexes of rep protein with ATP and DNA are manifested by ATP hydrolysis and by binding of labeled components. Nonhydrolyzed ATP analogs are useful aids for isolation and studies of such complexes. Unlike rep protein's processive action as a helicase at a replication fork, its action on single-stranded DNA is distributive, with ATP hydrolysis accelerating dissociation of the protein from the complex. These and related studies serve as guides to understanding the multiple interactions of rep protein with its ATP and DNA ligands that enable it to unwind duplex DNA at a replication fork.

Keywords: Adenosine Triphosphate Adenosinetriphosphatase/*METABOLISM Bacteriophage phi X 174/METABOLISM Carrier Proteins/METABOLISM Deoxyribonucleotides/PHARMACOLOGY Drug Combinations DNA/*METABOLISM DNA Helicases/*METABOLISM DNA Replication DNA, Single-Stranded/METABOLISM DNA, Viral/METABOLISM Escherichia coli/*ENZYMOLOGY Kinetics Polydeoxyribonucleotides Protein Binding Ribonucleotides/PHARMACOLOGY Substrate Specificity Support, Non-U.S. Gov't Support, U.S. Gov't, Non-P.H.S. Support, U.S. Gov't, P.H.S. JOURNAL ARTICLE

810930
M8190001

AEGiS is a 501(c)3, not-for-profit, tax-exempt, educational corporation. AEGiS is made possible through unrestricted funding from Boehringer Ingelheim, Bridgestone/Firestone Charitable Trust, Bristol-Myers Squibb Company, Elton John AIDS Foundation, Gill Foundation, the National Library of Medicine, Quest Diagnostics, Roche and Trimeris, and donations from users like you. Always watch for outdated information. This article first appeared in 1981. This material is designed to support, not replace, the relationship that exists between you and your doctor.

AEGiS presents published material, reprinted with permission and neither endorses nor opposes any material. All information contained on this website, including information relating to health conditions, products, and treatments, is for informational purposes only. It is often presented in summary or aggregate form. It is not meant to be a substitute for the advice provided by your own physician or other medical professionals. Always discuss treatment options with a doctor who specializes in treating HIV.

Copyright ©1980, 1981. AEGiS. All materials appearing on AEGiS are protected by copyright as a collective work or compilation under U.S. copyright and other laws and are the property of AEGiS, or the party credited as the provider of the content. .