Abstract
MutT-related proteins degrade 8-oxo-7,8-dihydrodeoxyguanosine triphosphate (8-oxo-dGTP), a mutagenic substrate for DNA synthesis, in the nucleotide pool, thereby preventing DNA replication errors. During a search of GenBank EST database, we found a new member of MutT-related protein, MTH2, which possesses the 23-amino acid MutT module. The cloned mouse MTH2 (mMTH2) cDNA was expressed in Escherichia coli mutT − cells and the protein was purified. mMTH2 protein hydrolyzes 8-oxo-dGTP to 8-oxo-dGMP, with Km of 32 μM. Expression of cDNA for mMTH2 reduced significantly the elevated level of spontaneous mutation frequency of E. coli mutT − cells. Thus, MTH2 has a potential to protect the genetic material from the untoward effects of endogenous oxygen radicals. MTH2 could act as an MTH1 redundancy factor.
Sign-in/Register to access full text options 
Free) 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a call
