MRNA guanylyltransferase

In enzymology, a mRNA guanylyltransferase (EC 2.7.7.50) is an enzyme that catalyzes the chemical reaction

GTP + (5')ppPur-mRNA ${\displaystyle \rightleftharpoons }$ diphosphate + G(5')pppPur-mRNA

Thus, the two substrates of this enzyme are GTP and (5')ppPur-mRNA, whereas its two products are diphosphate and G(5')pppPur-mRNA.

This enzyme belongs to the family of transferases, specifically those transferring phosphorus-containing nucleotide groups (nucleotidyltransferases).op The systematic name of this enzyme class is GTP:mRNA guanylyltransferase. Other names in common use include mRNA capping enzyme, messenger RNA guanylyltransferase, and Protein 2.

Structural studies

As of late 2007, 5 structures have been solved for this class of enzymes, with PDB accession codes 1CKM, 1CKN, 1CKO, 1P16, and 2C46.

References

• Ensinger MJ, Martin SA, Paoletti E, Moss B (1975). "Modification of the 5'-terminus of mRNA by soluble guanylyl and methyl transferases from vaccinia virus". Proc. Natl. Acad. Sci. U.S.A. 72 (7): 2525–9. Bibcode:1975PNAS...72.2525E. doi:10.1073/pnas.72.7.2525. PMC 432801. PMID 1058472.
• Groner Y, Gilboa E, Aviv H (1978). "Methylation and capping of RNA polymerase II primary transcripts by HeLa nuclear homogenates". Biochemistry. 17 (6): 977–82. doi:10.1021/bi00599a005. PMID 629955.
• Itoh N, Yamada H, Kaziro Y, Mizumoto K (1987). "Messenger RNA guanylyltransferase from Saccharomyces cerevisiae Large scale purification, subunit functions, and subcellular localization". J. Biol. Chem. 262 (5): 1989–95. doi:10.1016/S0021-9258(18)61609-6. PMID 3029058.
• Martin SA, Moss B (1975). "Modification of RNA by mRNA guanylyltransferase and mRNA (guanine-7-)methyltransferase from vaccinia virions". J. Biol. Chem. 250 (24): 9330–5. doi:10.1016/S0021-9258(19)40647-9. PMID 1194287.
• Martin SA, Paoletti E, Moss B (1975). "Purification of mRNA guanylyltransferase and mRNA (guanine-7-) methyltransferase from vaccinia virions". J. Biol. Chem. 250 (24): 9322–9. doi:10.1016/S0021-9258(19)40646-7. PMID 1194286.