| Structural highlights
5e8j is a 4 chain structure with sequence from Human. Full crystallographic information is available from OCA. For a guided tour on the structure components use FirstGlance.
| | Ligands: | , |
| Related: | 3bgv, 3epp |
| Gene: | RNMT, KIAA0398 (HUMAN), FAM103A1, C15orf18 (HUMAN) |
| Activity: | mRNA (guanine-N(7)-)-methyltransferase, with EC number 2.1.1.56 |
| Resources: | FirstGlance, OCA, PDBe, RCSB, PDBsum, ProSAT |
Function
[MCES_HUMAN] mRNA-capping methyltransferase that methylates the N7 position of the added guanosine to the 5'-cap structure of mRNAs. Binds RNA containing 5'-terminal GpppC.[1] [2] [3] [4] [RAM_HUMAN] Required for efficient mRNA cap methylation. Regulates RNMT expression by a post-transcriptional stabilizing mechanism.[5]
Publication Abstract from PubMed
Maturation and translation of mRNA in eukaryotes requires the addition of the 7-methylguanosine cap. In vertebrates, the cap methyltransferase, RNA guanine-7 methyltransferase (RNMT), has an activating subunit, RNMT-Activating Miniprotein (RAM). Here we report the first crystal structure of the human RNMT in complex with the activation domain of RAM. A relatively unstructured and negatively charged RAM binds to a positively charged surface groove on RNMT, distal to the active site. This results in stabilisation of a RNMT lobe structure which co-evolved with RAM and is required for RAM binding. Structure-guided mutagenesis and molecular dynamics simulations reveal that RAM stabilises the structure and positioning of the RNMT lobe and the adjacent alpha-helix hinge, resulting in optimal positioning of helix A which contacts substrates in the active site. Using biophysical and biochemical approaches, we observe that RAM increases the recruitment of the methyl donor, AdoMet (S-adenosyl methionine), to RNMT. Thus we report the mechanism by which RAM allosterically activates RNMT, allowing it to function as a molecular rheostat for mRNA cap methylation.
Molecular basis of RNA guanine-7 methyltransferase (RNMT) activation by RAM.,Varshney D, Petit AP, Bueren-Calabuig JA, Jansen C, Fletcher DA, Peggie M, Weidlich S, Scullion P, Pisliakov AV, Cowling VH Nucleic Acids Res. 2016 Jul 15. pii: gkw637. PMID:27422871[6]
From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine.
References
- ↑ Tsukamoto T, Shibagaki Y, Niikura Y, Mizumoto K. Cloning and characterization of three human cDNAs encoding mRNA (guanine-7-)-methyltransferase, an mRNA cap methylase. Biochem Biophys Res Commun. 1998 Oct 9;251(1):27-34. PMID:9790902 doi:http://dx.doi.org/S0006-291X(98)99402-5
- ↑ Pillutla RC, Yue Z, Maldonado E, Shatkin AJ. Recombinant human mRNA cap methyltransferase binds capping enzyme/RNA polymerase IIo complexes. J Biol Chem. 1998 Aug 21;273(34):21443-6. PMID:9705270
- ↑ Saha N, Schwer B, Shuman S. Characterization of human, Schizosaccharomyces pombe, and Candida albicans mRNA cap methyltransferases and complete replacement of the yeast capping apparatus by mammalian enzymes. J Biol Chem. 1999 Jun 4;274(23):16553-62. PMID:10347220
- ↑ Gonatopoulos-Pournatzis T, Dunn S, Bounds R, Cowling VH. RAM/Fam103a1 is required for mRNA cap methylation. Mol Cell. 2011 Nov 18;44(4):585-96. doi: 10.1016/j.molcel.2011.08.041. PMID:22099306 doi:http://dx.doi.org/10.1016/j.molcel.2011.08.041
- ↑ Gonatopoulos-Pournatzis T, Dunn S, Bounds R, Cowling VH. RAM/Fam103a1 is required for mRNA cap methylation. Mol Cell. 2011 Nov 18;44(4):585-96. doi: 10.1016/j.molcel.2011.08.041. PMID:22099306 doi:http://dx.doi.org/10.1016/j.molcel.2011.08.041
- ↑ Varshney D, Petit AP, Bueren-Calabuig JA, Jansen C, Fletcher DA, Peggie M, Weidlich S, Scullion P, Pisliakov AV, Cowling VH. Molecular basis of RNA guanine-7 methyltransferase (RNMT) activation by RAM. Nucleic Acids Res. 2016 Jul 15. pii: gkw637. PMID:27422871 doi:http://dx.doi.org/10.1093/nar/gkw637
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