label: histone H3K9 monomethyltransferase activity
label_lc: histone h3k9 monomethyltransferase activity
description: "Catalysis of the reaction: L-lysyl9-[histone H3] + S-adenosyl-L-methionine = H+ + N6-methyl-L-lysyl9-[histone H3] + S-adenosyl-L-homocysteine. This reaction is the addition of a methyl group to the unmethylated lysine residue at position 9 of histone H3, producing histone H3K9me."