ALKBH8 (AlkB Homolog 8), also called as ABH8 or TRMT9A, is a S-Adenosyl-L-Methionine-dependent tRNA methyltransferase. It catalyzes the methylation of 5-carboxymethyl uridine to 5-methylcarboxymethyl uridine at the wobble position of the anticodon loop in tRNA via its methyltransferase domain. It was reported to have a preference for tRNA(Arg) and tRNA(Glu), and does not bind tRNA(Lys). ALKBH8 can bind tRNA and catalyze the iron and alphaketoglutarate dependent hydroxylation of 5-methylcarboxymethyl uridine at the wobble position of the anticodon loop in tRNA via its dioxygenase domain, giving rise to 5-(S)-methoxycarbonylhydroxymethyluridine. It is also required for normal survival after DNA damage. ALKBH8 may inhibit apoptosis and promote cell survival and angiogenesis.
