Tobacco Acid Pyrophosphatase (TAP) is an enzyme that catalyses the hydrolysis of a phosphoric ester bond in a broad spectrum of molecules, including the 5'-end of mRNA.
During mRNA maturation the 5' triphosphate of the new mRNA molecule is rapidly removed. The diphosphate 5' end then attacks the α-phosphorus atom of a methylated GTP to form a very unusual 5'-5' triphosphate linkage, called cap. In molecular biology, TAP is used to hydrolyse a phosphodiester bond of this particular structure and release a mRNA molecule with only one phosphate group in the 5'-end, for instance in protocols for RACE (Rapid Amplification of cDNA Ends).
Commercial production of TAP was discontinued in 2015, however Cap-Clip acid pyrophosphatase has been found to perform nearly identically in genome-wide studies.
References
- Shinshi H, Miwa M, Kato K, Noguchi M, Matsushima T, Sugimura T (1976). "A novel phosphodiesterase from cultured tobacco cells". Biochemistry. 15 (10): 2185–90. doi:10.1021/bi00655a024. PMID 6041.
- JEREMY M. BERG; JOHN L. TYMOCZKOL; LUBERT STRYER (2002). Biochemistry (28.3.1 ed.).Online version
- Lockard, RE; Rieser, L; Vournakis JN. (1981). "Labeling of eukaryotic messenger RNA 5' terminus with phosphorus -32: use of tobacco acid pyrophosphatase for removal of cap structures". Gene Amplif Anal. 2: 229–51. PMID 6152889.
- Pelechano, Vicent; Wei, Wu; Steinmetz, Lars M. (February 2016). "Genome-wide quantification of 5′-phosphorylated mRNA degradation intermediates for analysis of ribosome dynamics". Nature Protocols. 11 (2): 359–376. doi:10.1038/nprot.2016.026. ISSN 1750-2799. PMC 4732566. PMID 26820793.