CMT3 — Arabidopsis thaliana

Summary

AT1G69770, known as CMT3 or chromomethylase 3, encodes a cytosine-specific DNA methyltransferase in Arabidopsis thaliana chromosome 1. The enzyme possesses DNA (cytosine-5-)-methyltransferase activity acting on CpN substrates (EC 2.1.1.37) and contains chromodomain and BAH domains characteristic of plant methyltransferases. CMT3 is associated with CpNpG and non-CG DNA methylation, transposable element silencing, and epigenetic gene silencing. It is linked to seed viability, embryo development, shoot morphogenesis, and regulation of nitrate assimilation. The protein localizes to both euchromatin and heterochromatin in the nucleus. CMT3 is associated with seed size, seed protein content, yield, germination rate, copper and nitrate content, photoperiod sensitivity, and Meloidogyne incognita resistance. Related genes in other species link the family to fruit ripening, paramutation, and disease resistance.