title: A bifunctional DNA repair protein from Ferroplasma acidarmanus exhibits O6-alkylguanine-DNA alkyltransferase and endonuclease V activities.
abstract: A recently discovered DNA repair protein of 303 aa from the archaeal organism Ferroplasma acidarmanus was studied. This protein (AGTendoV) consists of a fusion of the C-terminal active site domain of O(6)-alkylguanine-DNA alkyltransferase (AGT) with an endonuclease V domain. The AGTendoV recombinant protein expressed in Escherichia coli and purified to homogeneity repaired O(6)-methylguanine lesions in DNA via alkyl transfer action despite the complete absence of the N-terminal domain and some differences in key active site residues present in known AGTs. The AGTendoV recombinant protein also cleaved DNA substrates that contained the deaminated bases uracil, hypoxanthine, or xanthine in a similar manner to E. coli endonuclease V. Expression of AGTendoV in E. coli GWR109, a strain that lacks endogenous AGT activity, protected against both the killing and mutagenic activity of N-methyl-N'-nitro-N-nitrosoguanidine and was more effective in preventing mutations than human alkyltransferase, suggesting that the endonuclease V activity may also repair a promutagenic lesion produced by this alkylating agent. Expression of AGTendoV in a DNA repair-deficient E. coli nfi(-)alkA(-) strain protected from spontaneous mutations arising in saturated cultures and restored the mutation frequency to that found in the nfi(+) alkA(+) strain. These results demonstrate the physiological occurrence of two completely different but functional DNA repair activities in a single polypeptide chain.
authors.affiliation: Department of Cellular and Molecular Physiology, Pennsylvania State University College of Medicine, Hershey, PA 17033, USA.
authors.forename: Sreenivas
authors.initials: S
authors.lastname: Kanugula
authors.forename: Gary T
authors.initials: GT
authors.lastname: Pauly
authors.forename: Robert C
authors.initials: RC
authors.lastname: Moschel
authors.forename: Anthony E
authors.initials: AE
authors.lastname: Pegg
mesh_terms: D000595:Amino Acid Sequence; D019843:Archaeal Proteins / Q000737:chemistry / Q000378:metabolism*; D004260:DNA Repair; D043224:Deoxyribonuclease (Pyrimidine Dimer) / Q000378:metabolism*; D008969:Molecular Sequence Data; D019853:O(6)-Methylguanine-DNA Methyltransferase / Q000378:metabolism*; D019603:Thermoplasmales / Q000737:chemistry*
chemical_list: D019843:Archaeal Proteins; D019853:O(6)-Methylguanine-DNA Methyltransferase; D043224:Deoxyribonuclease (Pyrimidine Dimer)
references.citation: Mutat Res. 1999 Dec 7;435(3):245-54
references.pmid: 10606815
references.citation: Nucleic Acids Res. 2000 Jan 15;28(2):393-401
references.pmid: 10606635
references.citation: Science. 2000 Mar 10;287(5459):1796-9
references.pmid: 10710303
references.citation: Mutat Res. 2000 Mar 20;459(2):109-14
references.pmid: 10725661
references.citation: EMBO J. 2000 Apr 3;19(7):1719-30
references.pmid: 10747039
references.citation: Proc Natl Acad Sci U S A. 2000 Jun 6;97(12):6640-5
references.pmid: 10829079
references.citation: Appl Environ Microbiol. 2000 Sep;66(9):3842-9
references.pmid: 10966399
references.citation: Mutat Res. 2000 Nov 9;461(3):169-77
references.pmid: 11056288
references.citation: Mutat Res. 2001 Jan 5;461(4):301-9
references.pmid: 11104906
references.citation: Proc Natl Acad Sci U S A. 2001 Jul 3;98(14):7835-40
references.pmid: 11427726
references.citation: Chem Res Toxicol. 2001 Jul;14(7):894-900
references.pmid: 11453737
references.citation: Biochemistry. 2001 Jul 31;40(30):8738-48
references.pmid: 11467933
references.citation: Environ Mol Mutagen. 2001;38(2-3):235-43
references.pmid: 11746760
references.citation: Bioessays. 2002 Mar;24(3):255-66
references.pmid: 11891762
references.citation: Cancer Res. 2002 Jun 1;62(11):3037-43
references.pmid: 12036910
references.citation: Biochemistry. 2002 Jul 2;41(26):8342-50
references.pmid: 12081482
references.citation: Free Radic Biol Med. 2002 Oct 1;33(7):886-93
references.pmid: 12361800
references.citation: Biochemistry. 2003 Apr 1;42(12):3608-16
references.pmid: 12653565
references.citation: Nucleic Acids Res. 2003 Jul 15;31(14):3893-900
references.pmid: 12853604
references.citation: Cancer Gene Ther. 2003 Aug;10(8):603-10
references.pmid: 12872142
references.citation: Biochemistry. 2003 Sep 23;42(37):10965-70
references.pmid: 12974631
references.citation: J Biol Chem. 2004 Jun 25;279(26):26876-84
references.pmid: 15126496
references.citation: Nat Struct Mol Biol. 2004 Aug;11(8):714-20
references.pmid: 15221026
references.citation: Nucleic Acids Res. 2004;32(13):4071-80
references.pmid: 15289580
references.citation: J Biol Chem. 2004 Sep 10;279(37):38177-83
references.pmid: 15247209
references.citation: J Bacteriol. 1975 May;122(2):474-84
references.pmid: 1092652
references.citation: J Biol Chem. 1977 Mar 10;252(5):1647-53
references.pmid: 14159
references.citation: J Biol Chem. 1982 Mar 25;257(6):2848-55
references.pmid: 6277916
references.citation: Annu Rev Biochem. 1988;57:133-57
references.pmid: 3052269
references.citation: Proc Natl Acad Sci U S A. 1990 Jul;87(14):5368-72
references.pmid: 2164681
references.citation: J Bacteriol. 1991 Mar;173(6):2068-76
references.pmid: 2002008
references.citation: Carcinogenesis. 1991 Jun;12(6):949-55
references.pmid: 2044201
references.citation: Chem Res Toxicol. 1988 Nov-Dec;1(6):391-7
references.pmid: 2979756
references.citation: Mol Microbiol. 1992 Apr;6(7):825-31
references.pmid: 1602962
references.citation: Biochemistry. 1993 Nov 16;32(45):11998-2006
references.pmid: 8218276
references.citation: EMBO J. 1994 Apr 1;13(7):1495-501
references.pmid: 8156986
references.citation: Carcinogenesis. 1995 Aug;16(8):1687-92
references.pmid: 7634390
references.citation: Extremophiles. 1998 May;2(2):67-74
references.pmid: 9672680
references.citation: Nucleic Acids Res. 1999 Mar 1;27(5):1223-42
references.pmid: 9973609
references.citation: J Mol Biol. 1999 Sep 24;292(3):707-16
references.pmid: 10497033