InterPro domain: IPR029026

This entry represents the N-terminal domain of the tRNA (guanine-N1-)-methyltransferase. This domain forms a alpha/beta knot structure that is extremely rare in protein structures as it poses a folding problem [ 1 ]. This domain can also be found in the SPOUT superfamily members, including tRNA:Gm18 MTase TrmH [ 2 , 3 , 4 ].

1. Structure of the YibK methyltransferase from Haemophilus influenzae (HI0766): a cofactor bound at a site formed by a knot. Proteins 51, 56-67
2. The spoU gene of Escherichia coli, the fourth gene of the spoT operon, is essential for tRNA (Gm18) 2'-O-methyltransferase activity. Nucleic Acids Res. 25, 4093-7
3. Deep knot structure for construction of active site and cofactor binding site of tRNA modification enzyme. Structure 12, 593-602
4. The yfhQ gene of Escherichia coli encodes a tRNA:Cm32/Um32 methyltransferase. BMC Mol. Biol. 7, 23