5HJM

Crystal Structure of Pyrococcus abyssi Trm5a complexed with MTA

5HJM の概要

• エントリーDOI: 10.2210/pdb5hjm/pdb
• 関連するPDBエントリー: 5HJI 5HJJ 5HJK
• 分子名称: tRNA (guanine(37)-N1)-methyltransferase Trm5a, 5'-DEOXY-5'-METHYLTHIOADENOSINE, ACETATE ION, ... (5 entities in total)
• 機能のキーワード: methyltransferase, trm5a, sam, trna modification, transferase
• 由来する生物種: Pyrococcus abyssi (strain GE5 / Orsay)
• 細胞内の位置: Cytoplasm : Q9V2G1
• タンパク質・核酸の鎖数: 1
• 化学式量合計: 41215.99

構造登録者

Xie, W.,Wang, C.,Jia, Q. (登録日: 2016-01-13, 公開日: 2016-10-12, 最終更新日: 2023-11-08)

主引用文献

Wang, C.,Jia, Q.,Chen, R.,Wei, Y.,Li, J.,Ma, J.,Xie, W.
Crystal structures of the bifunctional tRNA methyltransferase Trm5a
Sci Rep, 6:33553-33553, 2016

PubMed Abstract: tRNA methyltransferase Trm5 catalyses the transfer of a methyl group from S-adenosyl-L-methionine to G37 in eukaryotes and archaea. The N1-methylated guanosine is the product of the initial step of the wyosine hypermodification, which is essential for the maintenance of the reading frame during translation. As a unique member of this enzyme family, Trm5a from Pyrococcus abyssi (PaTrm5a) catalyses not only the methylation of N1, but also the further methylation of C7 on 4-demethylwyosine at position 37 to produce isowyosine, but the mechanism for the double methylation is poorly understood. Here we report four crystal structures of PaTrm5a ranging from 1.7- to 2.3-Å, in the apo form or in complex with various SAM analogues. These structures reveal that Asp243 specifically recognises the base moiety of SAM at the active site. Interestingly, the protein in our structures all displays an extended conformation, quite different from the well-folded conformation of Trm5b from Methanocaldococcus jannaschii reported previously, despite their similar overall architectures. To rule out the possibilities of crystallisation artefacts, we conducted the fluorescence resonance energy transfer (FRET) experiments. The FRET data suggested that PaTrm5a adopts a naturally extended conformation in solution, and therefore the open conformation is a genuine state of PaTrm5a.

PubMed: 27629654
DOI: 10.1038/srep33553

実験手法

X-RAY DIFFRACTION (1.762 Å)