Nth Endonuclease III Like Protein 1 (NTHL1)

DNA N-glycosylases, or apurinic/apyrimidinic lyases, of the endonuclease III family, such as NTHL1, initiate DNA base excision repair of oxidized ring saturated pyrimidine residues.

The human NTH1 gene encodes a 312-amino acid polypeptide with a predicted mass of 34.3 kD. When expressed and purified, the protein had the same enzymatic activities as the E. coli enzyme: DNA glycosylase activity on DNA substrates containing oxidized pyrimidine residues, and apurinic/apyrimidinic lyase activity. NTHL1 contains 6 exons spanning approximately 8 kb of genomic DNA. Promoter analysis indicated a lack of TATA and CAAT boxes but the presence of a CpG island with binding sites for several transcription factors.