Actin-binding protein ABP140 is a methyltransferase for 3-methylcytidine at position 32 of tRNAs in Saccharomyces cerevisiae

The chemical structure of 3-methylcytidine and its position in tRNA^Thr1 and tRNA^Ser1. (A) Chemical structure of 3-methylcytidine (m³C). (B) Secondary structures of S. cerevisiae tRNA^Thr1 and tRNA^Ser1 with modified nucleosides: 3-methylcytidine (m³C), N²-methylguanosine (m²G), dihydrouridine (D), N²,N²-dimethylguanosine (m²₂G), inosine (I), N⁶-threonylcarbamoyladenosine (t⁶A), pseudouridine (Ψ), 5-methylcytidine (m⁵C), 5-methyluridine (m⁵U), 1-methyladenosine (m¹A), N⁴-acetylcytidine (ac⁴C), 2′-O-methylguanosine (Gm), 5-carbamoylmethyluridine (ncm⁵U), N⁶-isopentenyladenosine (i⁶A), and 2′-O-methyluridine (Um). Arrows indicate sites of RNase T₁ cleavage to generate RNA fragments containing residues at position 32.