Structural basis for substrate binding and catalytic mechanism of a human RNA:m5C methyltransferase NSun6.

ABSTRACT: 5-methylcytosine (m5C) modifications of RNA are ubiquitous in nature and play important roles in many biological processes such as protein translational regulation, RNA processing and stress response. Aberrant expressions of RNA:m5C methyltransferases are closely associated with various human diseases including cancers. However, no structural information for RNA-bound RNA:m5C methyltransferase was available until now, hindering elucidation of the catalytic mechanism behind RNA:m5C methylation. Here, we have solved the structures of NSun6, a human tRNA:m5C methyltransferase, in the apo form and in complex with a full-length tRNA substrate. These structures show a non-canonical conformation of the bound tRNA, rendering the base moiety of the target cytosine accessible to the enzyme for methy

SUBMITTER: Liu RJ 

PROVIDER: S-EPMC5499824 | biostudies-literature | 2017 Jun

REPOSITORIES: biostudies-literature