Display Settings:

Format

Send to:

Choose Destination
See comment in PubMed Commons below
Nucleic Acids Res. 1974 Jan;1(1):1-17.

Partial purification and characterization of four endodeoxyribonuclease activities from Escherichia coli K-12.

Abstract

Four hitherto undescribed endodeoxyribonucleases, temporarily designated A(1), A(2), A(3), and B, have been isolated from E. coli K-12. Each requires Mg(++) and is not stimulated by ATP or S-adenosylmethionine. A(3) is strongly inhibited by Fe(+++) and weakly inhibited by ATP, S-adenosylmethionine, and DPN, whereas B is inhibited by caffeine. Each can be purified free of exonuclease or DNA-3'-phosphatase. A(1) (molecular weight approximately 72,000) cleaves single-stranded, circular fd DNA to form 3'-hydroxyl termini and introduces nicks and breaks in the closed, double-stranded replicative form DNA of fd (fd RFI). A(2) (molecular weight approximately 46,000) cleaves fd DNA and introduces nicks and breaks in RFI, forming 3'-hydroxyl- and 5'-phosphoryl termini. A(3) (molecular weight approximately 38,000) cleaves fd DNA to form 3'-hydroxyl termini and introduces only nicks in fd RFI. Irradiation of the RFI with ultraviolet light markedly increases the rate of hydrolysis by A(3). B appears to form 3'-phosphoryl termini with fd DNA, but its characterization is highly preliminary due to its instability.

PMID:
10793655
[PubMed - indexed for MEDLINE]
PMCID:
PMC343319
Free PMC Article
PubMed Commons home

PubMed Commons

0 comments
How to join PubMed Commons

    Supplemental Content

    Full text links

    Icon for HighWire Icon for PubMed Central
    Loading ...
    Write to the Help Desk