Skip to main page content
U.S. flag

An official website of the United States government

Dot gov

The .gov means it’s official.
Federal government websites often end in .gov or .mil. Before sharing sensitive information, make sure you’re on a federal government site.

Https

The site is secure.
The https:// ensures that you are connecting to the official website and that any information you provide is encrypted and transmitted securely.

Access keys NCBI Homepage MyNCBI Homepage Main Content Main Navigation
. 1993 Apr 15;90(8):3211-5.
doi: 10.1073/pnas.90.8.3211.

Assembly of a functional replication complex without ATP hydrolysis: a direct interaction of bacteriophage T4 gp45 with T4 DNA polymerase

M K Reddy  1 , S E Weitzel, P H von Hippel
Affiliations

Assembly of a functional replication complex without ATP hydrolysis: a direct interaction of bacteriophage T4 gp45 with T4 DNA polymerase

M K Reddy et al. Proc Natl Acad Sci U S A. .

Abstract

The seven-protein bacteriophage T4 DNA replication complex can be manipulated in vitro to study mechanistic aspects of the elongation phase of DNA replication. Under physiological conditions, the processivity of DNA synthesis catalyzed by the T4 polymerase (gp43) is greatly increased by the interaction of this enzyme with its accessory proteins (gp44/62 and gp45) and the T4 single-stranded DNA binding protein (gp32). The assembly of this T4 holoenzyme requires hydrolysis of ATP by the gp44/62 complex. We demonstrate here that processive T4 holoenzyme-like DNA synthesis can be obtained without hydrolysis of ATP by simply adding gp45 to the T4 DNA polymerase at extremely high concentrations, effectively bypassing the ATPase subunits (gp44/62) of the accessory protein complex. The amount of gp45 required for the gp43-gp45 heteroassociation event is reduced by addition of the macromolecular crowding agent polyethylene glycol (PEG) as well as gp32. A chromatographic strategy involving PEG has been used to demonstrate the gp43-gp45 interaction. These results suggest that gp45 is ultimately responsible for increasing the processivity of DNA synthesis via a direct and functionally significant interaction with the T4 DNA polymerase. A corollary to this notion is that the specific role of the gp44/62 complex is to catalytically link gp45 to gp43.

PubMed Disclaimer

Similar articles

See all similar articles

Cited by

See all "Cited by" articles

References

    1. Biopolymers. 1970;9(9):1079-103 - PubMed
    1. Biochemistry. 1992 Sep 22;31(37):8675-90 - PubMed
    1. Proc Natl Acad Sci U S A. 1976 Oct;73(10):3511-5 - PubMed
    1. J Biol Chem. 1982 Oct 25;257(20):12435-43 - PubMed
    1. Proc Natl Acad Sci U S A. 1983 May;80(9):2442-6 - PubMed

Publication types

MeSH terms

LinkOut - more resources