5E9W

Crystal structure of mRNA cap guanine-N7 methyltransferase obtained by limited proteolysis

5E9W の概要

• エントリーDOI: 10.2210/pdb5e9w/pdb
• 関連するPDBエントリー: 5E8J
• 分子名称: mRNA cap guanine-N7 methyltransferase, S-ADENOSYL-L-HOMOCYSTEINE (3 entities in total)
• 機能のキーワード: mrna capping, transferase
• 由来する生物種: Homo sapiens (Human)
• タンパク質・核酸の鎖数: 4
• 化学式量合計: 148402.28

構造登録者

Petit, P.,Cowling, V.H. (登録日: 2015-10-15, 公開日: 2016-07-13, 最終更新日: 2024-01-10)

主引用文献

Varshney, D.,Petit, A.P.,Bueren-Calabuig, J.A.,Jansen, C.,Fletcher, D.A.,Peggie, M.,Weidlich, S.,Scullion, P.,Pisliakov, A.V.,Cowling, V.H.
Molecular basis of RNA guanine-7 methyltransferase (RNMT) activation by RAM.
Nucleic Acids Res., 44:10423-10436, 2016

PubMed Abstract: 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 α-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.

PubMed: 27422871
DOI: 10.1093/nar/gkw637

実験手法

X-RAY DIFFRACTION (2.283 Å)