Methionine Analogue Probes Functionally Important Residues in Active Site of Methionyl-tRNA Synthetase

  • Jo, Yeong-Joon (National Creative Research Initiatives Center for ARS Network) ;
  • Lee, Sang-Won (National Creative Research Initiatives Center for ARS Network) ;
  • Jo, Myung-Kyun (National Creative Research Initiatives Center for ARS Network) ;
  • Lee, Jee-Woo (College of Pharmacy, Seoul National University) ;
  • Kang, Mee-Kyoung (College of Pharmacy, Seoul National University) ;
  • Yoon, Jeong-Hyeok (ImaGene Company Sung Kyun Kwan University) ;
  • Kim, Sung-Hoon (National Creative Research Initiatives Center for ARS Network)
  • Received : 0
  • Accepted : 0
  • Published : 0

Abstract

Aminoacyl-tRNA synthetases are essential enzymes catalyzing the attachment of specific amino acids to cognate tRNAs. In the present work, the substrate analogue L-methionine hydroxamate was used to identify functional residues located in the active site of the E. coli methionyl-tRNA synthetase (MetRS). This compound inhibited bacteria, yeast, and human MetRS activities to a similar degree, suggesting a conserved active site structure and mechanism between MetRSs of different phylogenetic domains. Mutants of the E. coli MetRS resistant to methionine hydroxamate were also isolated. These mutants contained a substitution either at T10, Y15, or Y94. These residues are highly conserved among the different MetRSs and the mutants showed decreased aminoacylation activity, suggesting their functional and structural significances. The putative roles of these residues are discussed on a structural basis.

Keywords

Active site;Functional residues;L-Methionine hydroxamate;Methionyl-tRNA synthetase