AlkB, Alkylation Repair Homolog 3 (ALKBH3)

The Escherichia coli AlkB protein protects against the cytotoxicity of methylating agents by repair of the specific DNA lesions generated in single-stranded DNA. ALKBH2 and ALKBH3 are E. coli AlkB homologs that catalyze the removal of 1-methyladenine and 3-methylcytosine.The deduced protein shares 23.1% amino acid identity over the core region with E. coli AlkB and shares similarity to alpha-ketoglutarate/Fe(II)-dependent dioxygenases in the C-terminal region. It has a predicted tertiary structure with high similarity to the crystal structure of known dioxygenases. Northern blot analysis detected ALKBH3 expression in all tissues examined, as well as several carcinoma cell lines, with highest expression in spleen, prostate, bladder and colon.