Cysteine—tRNA ligase

In enzymology, a cysteine—tRNA ligase (EC 6.1.1.16) is an enzyme that catalyzes the chemical reaction:

ATP + L-cysteine + tRNACys ${\displaystyle \rightleftharpoons }$ AMP + diphosphate + L-cysteinyl-tRNACys

Cysteine—tRNA ligase
Identifiers
EC no.	6.1.1.16
CAS no.	37318-56-2
Databases
IntEnz	IntEnz view
BRENDA	BRENDA entry
ExPASy	NiceZyme view
KEGG	KEGG entry
MetaCyc	metabolic pathway
PRIAM	profile
PDB structures	RCSB PDB PDBe PDBsum
Gene Ontology	AmiGO / QuickGO
Search PMC articles PubMed articles NCBI proteins

The three substrates of this enzyme are ATP, L-cysteine, and tRNA(Cys), whereas its three products are AMP, diphosphate, and L-cysteinyl-tRNA(Cys).

This enzyme belongs to the family of ligases, specifically those forming carbon-oxygen bonds in aminoacyl-tRNA and related compounds. The systematic name of this enzyme class is L-cysteine:tRNACys ligase (AMP-forming). Other names in common use include cysteinyl-tRNA synthetase, cysteinyl-transferRNA synthetase, cysteinyl-transfer ribonucleate synthetase, and cysteine translase. This enzyme participates in cysteine metabolism and aminoacyl-tRNA biosynthesis.

Structural studies

As of late 2007, three structures have been solved for this class of enzymes, with PDB accession codes 1LI5, 1LI7, and 1U0B.