Human endonuclease V as a repair enzyme for DNA deamination

• Type of Material: Article
• Authors: Rongjuan Mi, Clemson University; Maria Alford-Zappala, State University of New York; Yoke Wah Kow, Emory University; Richard P. Cunningham, State University of New York; Weiguo Cao, Clemson University
• Language: English
• Date: 2012-07-01
• Publisher: Elsevier
• Publication Version: Author Accepted Manuscript (After Peer Review)
• Copyright Statement: © 2012 Elsevier B.V..
• License: Creative Commons Attribution-NonCommercial-NoDerivs 4.0 International
• Final Published Version (URL): http://dx.doi.org/10.1016/j.mrfmmm.2012.05.003
• Title of Journal or Parent Work: Mutation Research - Fundamental and Molecular Mechanisms of Mutagenesis
• ISSN: 0027-5107
• Volume: 735
• Issue: 1-2
• Start Page: 12
• End Page: 18
• Grant/Funding Information: This project was supported in part by CSREES/USDA (SC-1700274, technical contribution No. 5936), the Department of Defense (W81XWH-10-1-0385), and the National Institutes of Health (GM090141).; The research at The Emory University was supported by NIH grant CA90860 to Y.W.K.; The research at The University at Albany was supported by NIH grants GM46312 and CRR1 C06RR0154464 to R.P.C.
• Keywords: NITROUS-ACID; MUTATIONS; Nitrosative stress; HYPOXANTHINE; Endonuclease; Inosine; GLYCOSYLASE; RECOGNITION; Deamination; Life Sciences & Biomedicine; DIMP RESIDUES; THERMOTOGA-MARITIMA; Toxicology; CLEAVAGE; ESCHERICHIA-COLI K-12; Genetics & Heredity; Science & Technology; Biotechnology & Applied Microbiology; DEOXYINOSINE-SPECIFIC ENDONUCLEASE; Xanthosine; DNA repair
• Research Categories: Health Sciences, Toxicology; Biology, Genetics; Health Sciences, Oncology

Abstract

The human endonuclease V gene is located in chromosome 17q25.3 and encodes a 282 amino acid protein that shares about 30% sequence identity with bacterial endonuclease V. This study reports biochemical properties of human endonuclease V with respect to repair of deaminated base lesions. Using soluble proteins fused to thioredoxin at the N-terminus, we determined repair activities of human endonuclease V on deoxyinosine (I)-, deoxyxanthosine (X)-, deoxyoxanosine (O)- and deoxyuridine (U)-containing DNA. Human endonuclease V is most active with deoxyinosine-containing DNA but with minor activity on deoxyxanthosine-containing DNA. Endonuclease activities on deoxyuridine and deoxyoxanosine were not detected. The endonuclease activity on deoxyinosine-containing DNA follows the order of single-stranded I > G/I > T/I > A/I > C/I. The preference of the catalytic activity correlates with the binding affinity of these deoxyinosine-containing DNAs. Mg 2+ and to a much less extent, Mn 2+ , Ni 2+ , Co 2+ can support the endonuclease activity. Introduction of human endonuclease V into Escherichia coli cells deficient in nfi, mug and ung genes caused three-fold reduction in mutation frequency. This is the first report of deaminated base repair activity for human endonuclease V. The relationship between the endonuclease activity and deaminated deoxyadenosine (deoxyinosine) repair is discussed.