|Gene:||cca||Accession Numbers: EG10136 (EcoCyc), b3056, ECK3046|
Synonyms: CCA-adding enzyme
tRNA nucleotidyltransferase catalyzes the addition of CCA to the 3' ends of tRNAs in a template-independent manner [Cudny86]. Phosphatase, nucleotidase, and phosphodiesterase activities of CCA were discovered in a high-throughput screen of purified proteins, and these activities may act together to repair the 3' end of tRNA [Kuznetsova05].
All E. coli tRNAs encode the 3' CCA nucleotides as part of the gene [Komine90].
Polymerization of the CCA sequence does not appear to involve translocation of the enzyme [Shi98]. A model for the specific addition of CCA involving binding sites for ATP and CTP has been proposed [Tomari00, Seth02].
The N-terminal domain of the enzyme contains the nucleotidyltransferase activity. The C-terminal domain carries an HD motif found in a family of metal-dpendent phosphohydrolases and displays a variety of phosphohydrolase activities in the absence of tRNA [Yakunin04]. The C terminus of the protein contains an "anchor domain" of 27 amino acids that defines the addition of CCA versus poly(A), the activity of poly(A) polymerase [Betat04].
tRNA nucleotidyltransferase is not essential for viability of E. coli; a cca null mutant has a slow growth phenotype [Zhu87a]. Poly(A) polymerase I and polynucleotide phosphorylase can partially substitute for tRNA nucleotidyltransferase in the repair of the CCA end of tRNAs [Reuven97].
A cca mutant that is not impaired in incorporation of C, but can not add the A nucleotide at the end of tRNAs has been isolated [McGann80]; the point mutation was shown to lead to substitution of glycine at position 70 by aspartate [Zhu86].
Gene Citations: [Rhodius05]
|Map Position: [3,199,913 -> 3,201,151] (68.97 centisomes)||Length: 1239 bp / 412 aa|
Molecular Weight of Polypeptide: 46.467 kD (from nucleotide sequence), 47.0 kD (experimental) [Cudny86 ]
Unification Links: ASAP:ABE-0010031 , CGSC:933 , DIP:DIP-9250N , EchoBASE:EB0134 , EcoGene:EG10136 , EcoliWiki:b3056 , Mint:MINT-1263446 , ModBase:P06961 , OU-Microarray:b3056 , PortEco:cca , PR:PRO_000022254 , Protein Model Portal:P06961 , RefSeq:NP_417528 , RegulonDB:EG10136 , SMR:P06961 , String:511145.b3056 , UniProt:P06961
Relationship Links: InterPro:IN-FAMILY:IPR002646 , InterPro:IN-FAMILY:IPR003607 , InterPro:IN-FAMILY:IPR006674 , InterPro:IN-FAMILY:IPR012006 , Pfam:IN-FAMILY:PF01743 , Pfam:IN-FAMILY:PF01966 , Smart:IN-FAMILY:SM00471
In Paralogous Gene Group: 47 (2 members)
|Biological Process:||GO:0001680 - tRNA 3'-terminal CCA addition
[GOA06, GOA01a, GOA01, Deutscher77a, Cudny86]
GO:0042245 - RNA repair [UniProtGOA11, Reuven93]
GO:0006396 - RNA processing [GOA01]
GO:0008033 - tRNA processing [UniProtGOA11]
GO:0008152 - metabolic process [UniProtGOA11]
GO:0016311 - dephosphorylation [GOA06]
|Molecular Function:||GO:0004810 - tRNA adenylyltransferase activity
[GOA06, GOA01, Cudny86]
GO:0016437 - tRNA cytidylyltransferase activity [GOA06, Cudny86]
GO:0000049 - tRNA binding [GOA06]
GO:0000166 - nucleotide binding [UniProtGOA11]
GO:0000287 - magnesium ion binding [GOA06]
GO:0003723 - RNA binding [UniProtGOA11, GOA01]
GO:0003824 - catalytic activity [UniProtGOA11]
GO:0004112 - cyclic-nucleotide phosphodiesterase activity [GOA06]
GO:0005524 - ATP binding [UniProtGOA11, GOA06, GOA01]
GO:0016740 - transferase activity [UniProtGOA11]
GO:0016779 - nucleotidyltransferase activity [UniProtGOA11, GOA01]
GO:0016787 - hydrolase activity [UniProtGOA11]
GO:0016791 - phosphatase activity [GOA06]
GO:0046872 - metal ion binding [UniProtGOA11]
GO:0052927 - CTP:tRNA cytidylyltransferase activity [GOA01a]
GO:0052928 - CTP:3'-cytidine-tRNA cytidylyltransferase activity [GOA01a]
GO:0052929 - ATP:3'-cytidine-cytidine-tRNA adenylyltransferase activity [GOA01a]
|Cellular Component:||GO:0005737 - cytoplasm
GO:0005829 - cytosol [DiazMejia09]
|MultiFun Terms:||information transfer → RNA related → RNA modification|
|Growth Medium||Growth?||T (°C)||O2||pH||Osm/L||Growth Observations|
|LB Lennox||No||37||Aerobic||7||No [Baba06, Comment 1]|
Enzymatic reaction of: tRNA adenylyl-/cytidylyl-transferase (fused tRNA nucleotidyltransferase / 2',3'-cyclic phosphodiesterase / 2' nucleotidase and phosphatase)
Synonyms: tRNA cytidylyltransferase, tRNA CCA-pyrophosphorylase, tRNA CCA-diphosphorylase, CCA-adding enzyme
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 of enzyme catalysis.
The reaction is physiologically favored in the direction shown.
pH(opt): 9.4-10 [Cudny86]
10/20/97 Gene b3056 from Blattner lab Genbank (v. M52) entry merged into EcoCyc gene EG10136; confirmed by SwissProt match.
Baba06: Baba T, Ara T, Hasegawa M, Takai Y, Okumura Y, Baba M, Datsenko KA, Tomita M, Wanner BL, Mori H (2006). "Construction of Escherichia coli K-12 in-frame, single-gene knockout mutants: the Keio collection." Mol Syst Biol 2;2006.0008. PMID: 16738554
Best71: Best AN, Novelli GD (1971). "Studies with tRNA adenylyl(cytidylyl)transferase from Escherichia coli B. I. Purification and kinetic properties." Arch Biochem Biophys 142(2);527-38. PMID: 4927556
Best71a: Best AN, Novelli GD (1971). "Studies with tRNA adenylyl(cytidylyl)transferase from Escherichia coli B. II. Regulation of AMP and CMP incorporation into tRNApCpC and tRNApC." Arch Biochem Biophys 142(2);539-47. PMID: 4927557
Betat04: Betat H, Rammelt C, Martin G, Morl M (2004). "Exchange of regions between bacterial poly(A) polymerase and the CCA-adding enzyme generates altered specificities." Mol Cell 15(3);389-98. PMID: 15304219
Cudny86a: Cudny H, Lupski JR, Godson GN, Deutscher MP (1986). "Cloning, sequencing, and species relatedness of the Escherichia coli cca gene encoding the enzyme tRNA nucleotidyltransferase." J Biol Chem 261(14);6444-9. PMID: 3009457
Deutscher74: Deutscher MP (1974). "Preparation of cells permeable to macromolecules by treatment with toluene: studies of transfer ribonucleic acid nucleotidyltransferase." J Bacteriol 118(2);633-9. PMID: 4597454
Deutscher74a: Deutscher MP, Hilderman RH (1974). "Isolation and partial characterization of Escherichia coli mutants with low levels of transfer ribonucleic acid nucleotidyltransferase." J Bacteriol 118(2);621-7. PMID: 4597452
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
Hegg90: Hegg LA, Thurlow DL (1990). "Cytidines in tRNAs that are required intact by ATP/CTP:tRNA nucleotidyltransferases from Escherichia coli and Saccharomyces cerevisiae." Nucleic Acids Res 18(20);5975-9. PMID: 1700367
Kuznetsova05: Kuznetsova E, Proudfoot M, Sanders SA, Reinking J, Savchenko A, Arrowsmith CH, Edwards AM, Yakunin AF (2005). "Enzyme genomics: Application of general enzymatic screens to discover new enzymes." FEMS Microbiol Rev 29(2);263-79. PMID: 15808744
Miller71d: Miller JP, Philipps GR (1971). "Transfer ribonucleic acid nucleotidyltransferase from Escherichia coli. II. Purification, physical properties, and substrate specificity." J Biol Chem 246(5);1274-9. PMID: 5545070
Reuven97: Reuven NB, Zhou Z, Deutscher MP (1997). "Functional overlap of tRNA nucleotidyltransferase, poly(A) polymerase I, and polynucleotide phosphorylase." J Biol Chem 272(52);33255-9. PMID: 9407115
Yakunin04: Yakunin AF, Proudfoot M, Kuznetsova E, Savchenko A, Brown G, Arrowsmith CH, Edwards AM (2004). "The HD domain of the Escherichia coli tRNA nucleotidyltransferase has 2',3'-cyclic phosphodiesterase, 2'-nucleotidase, and phosphatase activities." J Biol Chem 279(35);36819-27. PMID: 15210699
Zhu86: Zhu LQ, Cudny H, Deutscher MP (1986). "A mutation in Escherichia coli tRNA nucleotidyltransferase that affects only AMP incorporation is in a sequence often associated with nucleotide-binding proteins." J Biol Chem 261(32);14875-7. PMID: 3533927
Gogol11: Gogol EB, Rhodius VA, Papenfort K, Vogel J, Gross CA (2011). "Small RNAs endow a transcriptional activator with essential repressor functions for single-tier control of a global stress regulon." Proc Natl Acad Sci U S A 108(31);12875-80. PMID: 21768388
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