Crystal structure of a methyltransferase involved in the biosynthesis of gentamicin in complex with (1R,2S,3S,4R,6R)-4,6-diamino-3-{[3-deoxy-4-C-methyl-3-(methylamino)-beta-L-arabinopyranosyl]oxy}-2-hydroxycyclohexyl 2-amino-2-deoxy-alpha-D-glucopyranoside
