6-羟基-2-氨甲基嘌呤

2-(Methylamino)-1H-purin-6(7H)-one (N2-methylguanine) is found within both helical and looped regions of RNA secondary structure, and it can exist in either the s-cis or the s-trans rotamer. If there is a rotational preference for the methyl group, the effect of 2-(Methylamino)-1H-purin-6(7H)-one substitution may be specific to the sequence context depending upon which face of the base participates in hydrogen bonding. 2-(Methylamino)-1H-purin-6(7H)-one (N2-methylguanine) is the principal kinetic barrier for reverse transcription in the 1340 bases proximal to the 5' end of E. coli 16S rRNA. Transcription intermediates correspond to attenuation at the positions of 2-(Methylamino)-1H-purin-6(7H)-one in the rRNA sequence. The relaxation time for elongation of the cDNA through m2G is approximately 3 min.