title: Relaxed tRNA specificity of the Staphylococcus aureus aspartyl-tRNA synthetase enables RNA-dependent asparagine biosynthesis.
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.
authors.affiliation: Chemistry Department, Skidmore College, Saratoga Springs, NY 12831, USA.
authors.forename: Stefani R
authors.initials: SR
authors.lastname: Mladenova
authors.affiliation: Chemistry Department, Skidmore College, Saratoga Springs, NY 12831, USA.
authors.forename: Kathryn R
authors.initials: KR
authors.lastname: Stein
authors.affiliation: Chemistry Department, Skidmore College, Saratoga Springs, NY 12831, USA.
authors.forename: Lianne
authors.initials: L
authors.lastname: Bartlett
authors.affiliation: Chemistry Department, Skidmore College, Saratoga Springs, NY 12831, USA. Electronic address: ksheppar@skidmore.edu.
authors.forename: Kelly
authors.initials: K
authors.lastname: Sheppard
mesh_terms: D000595:Amino Acid Sequence; D049148:Aminoacylation; D001216:Asparagine / Q000096:biosynthesis*; D001226:Aspartate-tRNA Ligase / Q000737:chemistry*; D004926:Escherichia coli / Q000235:genetics / Q000254:growth & development; D007700:Kinetics; D008969:Molecular Sequence Data; D012329:RNA, Bacterial / Q000737:chemistry / Q000235:genetics; D012348:RNA, Transfer, Asn / Q000737:chemistry* / Q000235:genetics; D012349:RNA, Transfer, Asp / Q000737:chemistry* / Q000235:genetics; D013211:Staphylococcus aureus / Q000201:enzymology*; D013379:Substrate Specificity
chemical_list: D012329:RNA, Bacterial; D012348:RNA, Transfer, Asn; D012349:RNA, Transfer, Asp; D001216:Asparagine; D001226:Aspartate-tRNA Ligase
keywords: Asparagine biosynthesis; Aspartyl-tRNA synthetase; RNA-dependent; Staphylococcus aureus; tRNA