Crystal Structure of tRNA<sup>His</sup> guanylyltransferase Reveals the Structural Basis of Reverse Nucleotide Polymerization

DOI Web Site 7 References
  • NAKAMURA Akiyoshi
    Bioproduction Reserch Institute, National Institute of Adcanced Industrial Science and Technology (AIST)

Bibliographic Information

Other Title
  • ヌクレオチドを3'末端から5'末端方向へと伸長する酵素の作用原理
  • ヌクレオチド オ 3'マッタン カラ 5'マッタン ホウコウ エ ト シンチョウ スル コウソ ノ サヨウ ゲンリ
  • Crystal Structure of tRNAHis guanylyltransferase Reveals the Structural Basis of Reverse Nucleotide Polymerization

Search this article

Description

During tRNA maturation tRNAHis guanylyltransferase (Thg1) catalyzes the untemplated 3'-5' addition of a G to the tRNA 5'-end. This additional guanylate provides the major identity element for histidyl-tRNA synthetase to recognize its cognate tRNAHis. Thg1 is a structural homolog of canonical 5'-3' polymerases. Here, we report the structures of Candida albicans Thg1 with its substrates tRNA, or ATP, or GTP. Two tRNAs bind to the tetrameric enzyme complex, but interaction of three subunits is required for tRNA positioning and catalytic activity. The tRNA substrate enters the Thg1 active site from the opposite direction compared to canonical 5'-3' polymerases, indicating that the directionality of nucleotide polymerization is strongly related to the directionality of substrate access. Structural and biochemical data support a reaction model of Thg1 that catalyzes reverse nucleotide addition.

Journal

References(7)*help

See more

Keywords

Details 詳細情報について

Report a problem

Back to top