Comprehensive structure-function characterization of DNMT3B and DNMT3A reveals distinctive de novo DNA methylation mechanisms
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ABSTRACT: Mammalian DNA methylation patterns are established by two de novo DNA methyltransferases DNMT3A and DNMT3B, which exhibit both redundant and distinctive methylation activities. However, the related molecular basis remains undetermined. Through comprehensive structural, enzymology and cellular characterizations of DNMT3A and DNMT3B, here we uncovered distinct and interrelated modes-of-action underlying their CpG site and flanking sequence interaction. Strikingly, K777 of DNMT3B makes direct contacts with the DNA base at the +1 flank position of the cytosine methylation site, which contrasts with its counterpart in DNMT3A that forms base-specific contacts with the CpG site. Consequently, there is a divergent substrate and flanking sequence preference between DNMT3A and DNMT3B in vitro and in cells, thus providing an explanation for site-specific epigenomic alterations seen in ICF syndrome patients with DNMT3B mutations. Together, this study reveals crucial, yet complicated interplays of DNMT3s, DNA sequences and resultant methylation.
ORGANISM(S): Mus musculus
PROVIDER: GSE145899 | GEO | 2020/06/18
REPOSITORIES: GEO
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