MCB
Home Help [Feedback] [For Subscribers] [Archive] [Search] [Contents]
This Article
Right arrow Full Text
Right arrow Full Text (PDF)
Right arrow Alert me when this article is cited
Right arrow Alert me if a correction is posted
Services
Right arrow Similar articles in this journal
Right arrow Similar articles in PubMed
Right arrow Alert me to new issues of the journal
Right arrow Download to citation manager
Right arrowReprints and Permissions
Right arrow Copyright Information
Right arrow Books from ASM Press
Right arrow MicrobeWorld
Citing Articles
Right arrow Citing Articles via HighWire
Right arrow Citing Articles via Google Scholar
Google Scholar
Right arrow Articles by Unk, I.
Right arrow Articles by Prakash, L.
Right arrow Search for Related Content
PubMed
Right arrow PubMed Citation
Right arrow Articles by Unk, I.
Right arrow Articles by Prakash, L.

 Previous Article  |  Next Article 

Molecular and Cellular Biology, March 2001, p. 1656-1661, Vol. 21, No. 5
0270-7306/01/$04.00+0   DOI: 10.1128/MCB.21.5.1656-1661.2001
Copyright © 2001, American Society for Microbiology. All rights reserved.

3'-Phosphodiesterase and 3'right-arrow 5' Exonuclease Activities of Yeast Apn2 Protein and Requirement of These Activities for Repair of Oxidative DNA Damage

Ildiko Unk, Lajos Haracska, Satya Prakash, and Louise Prakash*

Sealy Center for Molecular Science, University of Texas Medical Branch, Galveston, Texas 77555-1061

Received 26 October 2000/Returned for modification 16 November 2000/Accepted 28 November 2000

In Saccharomyces cerevisiae, the AP endonucleases encoded by the APN1 and APN2 genes provide alternate pathways for the removal of abasic sites. Oxidative DNA-damaging agents, such as H2O2, produce DNA strand breaks which contain 3'-phosphate or 3'-phosphoglycolate termini. Such 3' termini are inhibitory to synthesis by DNA polymerases. Here, we show that purified yeast Apn2 protein contains 3'-phosphodiesterase and 3'right-arrow5' exonuclease activities, and mutation of the active-site residue Glu59 to Ala in Apn2 inactivates both these activities. Consistent with these biochemical observations, genetic studies indicate the involvement of APN2 in the repair of H2O2-induced DNA damage in a pathway alternate to APN1, and the Ala59 mutation inactivates this function of Apn2. From these results, we conclude that the ability of Apn2 to remove 3'-end groups from DNA is paramount for the repair of strand breaks arising from the reaction of DNA with reactive oxygen species.

* Corresponding author. Mailing address: University of Texas Medical Branch, Sealy Center for Molecular Science, 6.104 Medical Research Building, 11th and Mechanic St., Galveston, TX 77555-1061. Phone: (409) 747-8601. Fax: (409) 747-8608. E-mail: lprakash{at}scms.utmb.edu.

Molecular and Cellular Biology, March 2001, p. 1656-1661, Vol. 21, No. 5
0270-7306/01/$04.00+0   DOI: 10.1128/MCB.21.5.1656-1661.2001
Copyright © 2001, American Society for Microbiology. All rights reserved.


This article has been cited by other articles:



Home Help [Feedback] [For Subscribers] [Archive] [Search] [Contents]
J. Bacteriol. J. Virol. Eukaryot. Cell
Microbiol. Mol. Biol. Rev. Clin. Vaccine Immunol. All ASM Journals

Copyright © 2001 by the American Society for Microbiology. All rights reserved.