Table 1.

N7-methylguanosine methyltransferase in tRNA.

Domains of Life	Organisms	Positions of m7G	Enzyme Names	Higher Order Structure	References
eubacteria	E. coli	46	TrmB	monomer	[21,22]
	A. aeolicus	46	TrmB	monomer	[23,24,25]
	T. thermophilus	46	TrmB	?	[26]
	B. subtilis	46	TrmB	homodimer	[27]
	S. pneumoniae	46	TrmB	homodimer	PDB: 1YZH
archaea	T. acidophilum	49 (tRNALeu(UAG))	?	?	[7,20]
	T. neutrophilus	?	?	?	[7]
eukaryote	S. cerevisiae	46	Trm8/Trm82	heterodimer	[28,29,30]
	S. cerevisiae	5′ termini of pre-tRNA	Ceg1p	?	[31]
	C. lagenarium	46	Aph1	?	[32]
	human	46	METTL1/WDR4	?	[21,28]
	C. reinhardtii	37 (chloroplast tRNALeu(UAG))	?	?	[16]
	A. amurensis	34 (mt tRNASer(GCU))	?	?	[17,19]
	L. bleekeri	34 (mt tRNASer(GCU))	?	?	[18,19]

Unidentified m⁷G positions, enzymes, and higher order structures are indicated by question marks.