CCA tRNA nucleotidyltransferase explained

CCA tRNA nucleotidyltransferase
Ec Number:	2.7.7.72

CCA tRNA nucleotidyltransferase (CCA-adding enzyme, tRNA adenylyltransferase, tRNA CCA-pyrophosphorylase, tRNA-nucleotidyltransferase, transfer-RNA nucleotidyltransferase, transfer ribonucleic acid nucleotidyl transferase, CTP(ATP):tRNA nucleotidyltransferase, transfer ribonucleate adenylyltransferase, transfer ribonucleate adenyltransferase, transfer RNA adenylyltransferase, transfer ribonucleate nucleotidyltransferase, ATP (CTP):tRNA nucleotidyltransferase, ribonucleic cytidylic cytidylic adenylic pyrophosphorylase, transfer ribonucleic adenylyl (cytidylyl) transferase, transfer ribonucleic-terminal trinucleotide nucleotidyltransferase, transfer ribonucleate cytidylyltransferase, ribonucleic cytidylyltransferase, -C-C-A pyrophosphorylase, ATP(CTP)-tRNA nucleotidyltransferase, tRNA adenylyl(cytidylyl)transferase, CTP:tRNA cytidylyltransferase) is an enzyme with systematic name CTP,CTP,ATP:tRNA cytidylyl,cytidylyl,adenylyltransferase.^{[1] [2] [3] [4] [5]} This enzyme catalyses the following chemical reaction

a tRNA precursor + 2 CTP + ATP

\rightleftharpoons a tRNA with a 3' CCA end + 3 diphosphate (overall reaction)

(1a) a tRNA precursor + CTP

\rightleftharpoons a tRNA with a 3' cytidine end + diphosphate

(1b) a tRNA with a 3' cytidine + CTP

\rightleftharpoons a tRNA with a 3' CC end + diphosphate

(1c) a tRNA with a 3' CC end + ATP

\rightleftharpoons a tRNA with a 3' CCA end + diphosphate

The acylation of all tRNAs with an amino acid occurs at the terminal ribose of a 3' CCA sequence.

See also

• TRNT1

Notes and References

1. Schofield P, Williams KR . Purification and some properties of Escherichia coli tRNA nucleotidyltransferase . The Journal of Biological Chemistry . 252 . 15 . 5584–8 . August 1977 . 328503 .
2. Shi PY, Maizels N, Weiner AM . CCA addition by tRNA nucleotidyltransferase: polymerization without translocation? . The EMBO Journal . 17 . 11 . 3197–206 . June 1998 . 9606201 . 1170658 . 10.1093/emboj/17.11.3197 .
3. Augustin MA, Reichert AS, Betat H, Huber R, Mörl M, Steegborn C . Crystal structure of the human CCA-adding enzyme: insights into template-independent polymerization . Journal of Molecular Biology . 328 . 5 . 985–94 . May 2003 . 12729736 . 10.1016/S0022-2836(03)00381-4 . free .
4. Yakunin AF, Proudfoot M, Kuznetsova E, Savchenko A, Brown G, Arrowsmith CH, Edwards AM . The HD domain of the Escherichia coli tRNA nucleotidyltransferase has 2',3'-cyclic phosphodiesterase, 2'-nucleotidase, and phosphatase activities . The Journal of Biological Chemistry . 279 . 35 . 36819–27 . August 2004 . 15210699 . 10.1074/jbc.M405120200 . free .
5. Hou YM . CCA addition to tRNA: implications for tRNA quality control . IUBMB Life . 62 . 4 . 251–60 . April 2010 . 20101632 . 2848691 . 10.1002/iub.301 .