A novel uracil-DNA glycosylase family related to the helix-hairpin-helix DNA glycosylase superfamily.
Cytosine bases can be deaminated spontaneously to uracil, causing DNA damage. Uracil-DNA glycosylase (UDG), a ubiquitous uracil-excising enzyme found in bacteria and eukaryotes, is one of the enzymes that repair this kind of DNA damage. To date, no UDG-coding gene has been identified in Methanococcus jannaschii, although its entire genome was deciphered. Here, we have identified and characterized a novel UDG from M.jannaschii designated as MjUDG. It efficiently removed uracil from both single- and double-stranded DNA. MjUDG also catalyzes the excision of 8-oxoguanine from DNA. MjUDG has a helix-hairpin-helix motif and a [4Fe-4S]-binding cluster that is considered to be important for the DNA binding and catalytic activity. Although MjUDG shares these features with other structural families such as endonuclease III and mismatch-specific DNA glycosylase (MIG), unique conserved amino acids and substrate specificity distinguish MjUDG from other families. Also, a homologous member of MjUDG was identified in Aquifex aeolicus. We report that MjUDG belongs to a novel UDG family that has not been described to date.
Chung
Ji Hyung
JH
Yonsei Research Institute of Aging Science, Yonsei University College of Medicine, Yonsei University, Seoul, 120-752, Korea.
Im
Eun Kyoung
EK
Park
Hyun-Young
HY
Kwon
Jun Hye
JH
Lee
Seahyoung
S
Oh
Jaewon
J
Hwang
Ki-Chul
KC
Lee
Jong Ho
JH
Jang
Yangsoo
Y
D000595:Amino Acid Sequence; D019843:Archaeal Proteins / Q000235:genetics / Q000302:isolation & purification / Q000378:metabolism; D045647:DNA Glycosylases; D004260:DNA Repair; D004926:Escherichia coli / Q000235:genetics; D006151:Guanosine / Q000031:analogs & derivatives* / Q000378:metabolism; D017017:Methanococcus / Q000201:enzymology / Q000235:genetics; D008969:Molecular Sequence Data; D009699:N-Glycosyl Hydrolases / Q000235:genetics / Q000302:isolation & purification / Q000378:metabolism*; D009841:Oligonucleotides / Q000378:metabolism; D010802:Phylogeny; D011994:Recombinant Proteins / Q000235:genetics / Q000378:metabolism; D017386:Sequence Homology, Amino Acid; D013379:Substrate Specificity; D051981:Uracil-DNA Glycosidase
D019843:Archaeal Proteins; D009841:Oligonucleotides; D011994:Recombinant Proteins; D006151:Guanosine; C046215:8-hydroxyguanosine; D045647:DNA Glycosylases; D009699:N-Glycosyl Hydrolases; D051981:Uracil-DNA Glycosidase; C076131:DNA-3-methyladenine glycosidase II