|Gene:||cysS||Accession Numbers: EG10196 (MetaCyc), b0526, ECK0519|
Species: Escherichia coli K-12 substr. MG1655
Cysteinyl-tRNA synthetase (CysRS) is a member of the family of aminoacyl-tRNA synthetases, which interpret the genetic code by covalently linking amino acids to their specific tRNA molecules. The reaction is driven by ATP hydrolysis. CysRS belongs to the Class I aminoacyl tRNA synthetases [Eriani90, Landes95].
CysRS is a monomer in solution [Eriani91]. The N-terminal domain of CysRS is active in adenylate synthesis, while the C-terminal domain is able to bind and discriminate tRNA. The two domains can not complement each other in trans, showing that full enzymatic activity requires covalent continuity [Zhang05a]. Molecular dynamics analysis of the enzyme has allowed identification of key residues involved in communication between the two domains, and kinetic analysis of mutant enzymes confirmed their importance [Ghosh11].
Specificity determinants within tRNACys that are important for recognition by CysRS have been identified [Pallanck92, Hou93, Komatsoulis93, Hou95, Hou95a, Christian00, Hou01]. Specificity determinants and residues within CysRS that are important for catalytic activity have been investigated [Ohannesian96]. Recognition of the 1-72 base pair of the tRNA acceptor end is accomplished by an α-helical motif insertion in the Rossmann-fold domain of CysRS [Liu12].
A crystal structure of CysRS bound to tRNACys was determined at 2.3 Å resolution, showing extensive base-selective and shape-specific RNA-protein interactions [Hauenstein04]. The efficiency of CysRS aminoacylation is modulated by the G15-G48 Levitt pair together with tertiary nucleotides surrounding it in tRNACys [Sherlin00].
Investigation of pre-steady-state and single turnover kinetics of CysRS show that the enzyme exhibits burst kinetics and is rate-limited by release of aminoacyl-tRNA, distinguishing it from class II aminoacyl tRNA synthetases [Zhang06].
Unlike other aminoacyl-tRNA synthetases, CysRS does not possess an editing mechanism to discriminate against non-cognate amino acids [Fersht79]. Crystal structures of CysRS in the apo- and cysteine-bound state have been determined at 2.3 and 2.6 Å resolution, revealing a zinc ion at the base of the active site cleft [Newberry02]. The zinc ion is responsible for the ability of CysRS to bind cysteine specifically, although CysRS does not possess amino acid editing activity [Zhang03f, Zhang03g].
Unlike other class I aminoacyl-tRNA synthetases, CysRS is able to attach cysteine to both the 2' and 3' hydroxyl groups of A76 in tRNACys. However, aminoacylation of the 3' hydroxyl group has a 20-fold lower kcat/Km than that of the 2' hydroxyl group. The conserved nucleotide U73 in tRNACys appears to confer this flexibility [Shitivelband05].
|Map Position: [553,834 -> 555,219]|
Molecular Weight of Polypeptide: 52.202 kD (from nucleotide sequence), 55 kD (experimental) [Hou91 ]
Unification Links: ASAP:ABE-0001810 , CGSC:888 , DIP:DIP-9386N , EchoBASE:EB0193 , EcoGene:EG10196 , EcoliWiki:b0526 , Mint:MINT-1240309 , ModBase:P21888 , OU-Microarray:b0526 , PortEco:cysS , PR:PRO_000022387 , Pride:P21888 , Protein Model Portal:P21888 , RefSeq:NP_415059 , RegulonDB:EG10196 , SMR:P21888 , String:511145.b0526 , UniProt:P21888
Relationship Links: InterPro:IN-FAMILY:IPR009080 , InterPro:IN-FAMILY:IPR014729 , InterPro:IN-FAMILY:IPR015273 , InterPro:IN-FAMILY:IPR015803 , InterPro:IN-FAMILY:IPR024909 , Panther:IN-FAMILY:PTHR10890 , PDB:Structure:1LI5 , PDB:Structure:1LI7 , PDB:Structure:1U0B , Pfam:IN-FAMILY:PF01406 , Pfam:IN-FAMILY:PF09190 , Prints:IN-FAMILY:PR00983 , Prosite:IN-FAMILY:PS00178 , Smart:IN-FAMILY:SM00840
|Biological Process:||GO:0006423 - cysteinyl-tRNA aminoacylation
[GOA06, GOA01a, Zhang03f]
GO:0006412 - translation [UniProtGOA11a]
GO:0006418 - tRNA aminoacylation for protein translation [GOA01a]
|Molecular Function:||GO:0004812 - aminoacyl-tRNA ligase activity
[UniProtGOA11a, GOA01a, Zhang03f]
GO:0004817 - cysteine-tRNA ligase activity [GOA06, GOA01, GOA01a, Zhang03f]
GO:0005524 - ATP binding [UniProtGOA11a, GOA06, GOA01a, Newberry02]
GO:0008270 - zinc ion binding [GOA06, Newberry02, Zhang03f]
GO:0016874 - ligase activity [UniProtGOA11a, Zhang03f]
GO:0046872 - metal ion binding [UniProtGOA11a, Zhang03f]
GO:0000166 - nucleotide binding [UniProtGOA11a, GOA01a]
|Cellular Component:||GO:0005829 - cytosol
[DiazMejia09, Ishihama08, Gaudet10]
GO:0005737 - cytoplasm [UniProtGOA11, UniProtGOA11a, GOA06, GOA01a]
|MultiFun Terms:||information transfer → protein related → amino acid -activation|
Enzymatic reaction of: cysteinyl-tRNA synthetase
EC Number: 18.104.22.168
The reaction direction shown, that is, A + B ↔ C + D versus C + D ↔ A + B, is in accordance with the direction in which it was curated.
The reaction is physiologically favored in the direction shown.
In Pathways: tRNA charging
|Protein-Segment||30 -> 40|
|Protein-Segment||266 -> 270|
10/20/97 Gene b0526 from Blattner lab Genbank (v. M52) entry merged into EcoCyc gene EG10196; confirmed by SwissProt match.
DiazMejia09: Diaz-Mejia JJ, Babu M, Emili A (2009). "Computational and experimental approaches to chart the Escherichia coli cell-envelope-associated proteome and interactome." FEMS Microbiol Rev 33(1);66-97. PMID: 19054114
Eriani90: Eriani G, Delarue M, Poch O, Gangloff J, Moras D (1990). "Partition of tRNA synthetases into two classes based on mutually exclusive sets of sequence motifs." Nature 347(6289);203-6. PMID: 2203971
Eriani91: Eriani G, Dirheimer G, Gangloff J (1991). "Cysteinyl-tRNA synthetase: determination of the last E. coli aminoacyl-tRNA synthetase primary structure." Nucleic Acids Res 19(2);265-9. PMID: 2014166
Fersht79: Fersht AR, Dingwall C (1979). "Cysteinyl-tRNA synthetase from Escherichia coli does not need an editing mechanism to reject serine and alanine. High binding energy of small groups in specific molecular interactions." Biochemistry 18(7);1245-9. PMID: 371674
Ghosh11: Ghosh A, Sakaguchi R, Liu C, Vishveshwara S, Hou YM (2011). "Allosteric communication in cysteinyl tRNA synthetase: a network of direct and indirect readout." J Biol Chem 286(43);37721-31. PMID: 21890630
Hou91: Hou YM, Shiba K, Mottes C, Schimmel P (1991). "Sequence determination and modeling of structural motifs for the smallest monomeric aminoacyl-tRNA synthetase." Proc Natl Acad Sci U S A 88(3);976-80. PMID: 1992490
Landes95: Landes C, Perona JJ, Brunie S, Rould MA, Zelwer C, Steitz TA, Risler JL (1995). "A structure-based multiple sequence alignment of all class I aminoacyl-tRNA synthetases." Biochimie 77(3);194-203. PMID: 7647112
Liu12: Liu C, Sanders JM, Pascal JM, Hou YM (2012). "Adaptation to tRNA acceptor stem structure by flexible adjustment in the catalytic domain of class I tRNA synthetases." RNA 18(2);213-21. PMID: 22184460
Ruan04: Ruan B, Nakano H, Tanaka M, Mills JA, DeVito JA, Min B, Low KB, Battista JR, Soll D (2004). "Cysteinyl-tRNA(Cys) formation in Methanocaldococcus jannaschii: the mechanism is still unknown." J Bacteriol 186(1);8-14. PMID: 14679218
Sherlin00: Sherlin LD, Bullock TL, Newberry KJ, Lipman RS, Hou YM, Beijer B, Sproat BS, Perona JJ (2000). "Influence of transfer RNA tertiary structure on aminoacylation efficiency by glutaminyl and cysteinyl-tRNA synthetases." J Mol Biol 299(2);431-46. PMID: 10860750
Zhang08a: Zhang CM, Liu C, Christian T, Gamper H, Rozenski J, Pan D, Randolph JB, Wickstrom E, Cooperman BS, Hou YM (2008). "Pyrrolo-C as a molecular probe for monitoring conformations of the tRNA 3' end." RNA 14(10);2245-53. PMID: 18755841
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