Relaxed tRNA specificity of the Staphylococcus aureus aspartyl-tRNA synthetase enables RNA-dependent asparagine biosynthesis

FEBS Lett. 2014 May 2;588(9):1808-12. doi: 10.1016/j.febslet.2014.03.042. Epub 2014 Mar 28.

Abstract

The human pathogen Staphylococcus aureus is an asparagine prototroph despite its genome not encoding an asparagine synthetase. S. aureus does use an asparaginyl-tRNA synthetase (AsnRS) to directly ligate asparagine to tRNA(Asn). The S. aureus genome also codes for one aspartyl-tRNA synthetase (AspRS). Here we demonstrate the lone S. aureus aspartyl-tRNA synthetase has relaxed tRNA specificity and can be used with the amidotransferase GatCAB to synthesize asparagine on tRNA(Asn). S. aureus thus encodes both the direct and indirect routes for Asn-tRNA(Asn) formation while encoding only one aspartyl-tRNA synthetase. The presence of the indirect pathway explains how S. aureus synthesizes asparagine without either asparagine synthetase.

Keywords: Asparagine biosynthesis; Aspartyl-tRNA synthetase; RNA-dependent; Staphylococcus aureus; tRNA.

Publication types

  • Research Support, Non-U.S. Gov't
  • Research Support, U.S. Gov't, Non-P.H.S.

MeSH terms

  • Amino Acid Sequence
  • Aminoacylation
  • Asparagine / biosynthesis*
  • Aspartate-tRNA Ligase / chemistry*
  • Escherichia coli / genetics
  • Escherichia coli / growth & development
  • Kinetics
  • Molecular Sequence Data
  • RNA, Bacterial / chemistry
  • RNA, Bacterial / genetics
  • RNA, Transfer, Asn / chemistry*
  • RNA, Transfer, Asn / genetics
  • RNA, Transfer, Asp / chemistry*
  • RNA, Transfer, Asp / genetics
  • Staphylococcus aureus / enzymology*
  • Substrate Specificity

Substances

  • RNA, Bacterial
  • RNA, Transfer, Asn
  • RNA, Transfer, Asp
  • Asparagine
  • Aspartate-tRNA Ligase