Structural and biochemical insights into 2'-O-methylation at the 3'-terminal nucleotide of RNA by Hen1.

ABSTRACT: Small RNAs of approximately 20-30 nt have diverse and important biological roles in eukaryotic organisms. After being generated by Dicer or Piwi proteins, all small RNAs in plants and a subset of small RNAs in animals are further modified at their 3'-terminal nucleotides via 2'-O-methylation, carried out by the S-adenosylmethionine-dependent methyltransferase (MTase) Hen1. Methylation at the 3' terminus is vital for biological functions of these small RNAs. Here, we report four crystal structures of the MTase domain of a bacterial homolog of Hen1 from Clostridium thermocellum and Anabaena variabilis, which are enzymatically indistinguishable from the eukaryotic Hen1 in their ability to methylate small single-stranded RNAs. The structures reveal that, in addition to the core fold of the MTa

SUBMITTER: Mui Chan C 

PROVIDER: S-EPMC2764946 | biostudies-literature | 2009 Oct

REPOSITORIES: biostudies-literature