6F87

Crystal structure of P. abyssi Sua5 complexed with L-threonine and PPi

6F87 の概要

• エントリーDOI: 10.2210/pdb6f87/pdb
• 分子名称: Threonylcarbamoyl-AMP synthase, PYROPHOSPHATE 2-, THREONINE, ... (4 entities in total)
• 機能のキーワード: nucleotidyltransferase, trna modification, threonylcarbamoylation, transferase
• 由来する生物種: Pyrococcus abyssi (strain GE5 / Orsay)
• タンパク質・核酸の鎖数: 4
• 化学式量合計: 153968.94

構造登録者

Pichard-Kostuch, A.,Zhang, W.,Liger, D.,Daugeron, M.C.,Letoquart, J.,Li de la Sierra-Gallay, I.,Forterre, P.,Collinet, B.,van Tilbeurgh, H.,Basta, T. (登録日: 2017-12-12, 公開日: 2018-04-25, 最終更新日: 2024-01-17)

主引用文献

Pichard-Kostuch, A.,Zhang, W.,Liger, D.,Daugeron, M.C.,Letoquart, J.,Li de la Sierra-Gallay, I.,Forterre, P.,Collinet, B.,van Tilbeurgh, H.,Basta, T.
Structure-function analysis of Sua5 protein reveals novel functional motifs required for the biosynthesis of the universal t6A tRNA modification.
RNA, 24:926-938, 2018

PubMed Abstract: -threonyl-carbamoyl adenosine (tA) is a universal tRNA modification found at position 37, next to the anticodon, in almost all tRNAs decoding ANN codons (where N = A, U, G, or C). tA stabilizes the codon-anticodon interaction and hence promotes translation fidelity. The first step of the biosynthesis of tA, the production of threonyl-carbamoyl adenylate (TC-AMP), is catalyzed by the Sua5/TsaC family of enzymes. While TsaC is a single domain protein, Sua5 enzymes are composed of the TsaC-like domain, a linker and an extra domain called SUA5 of unknown function. In the present study, we report structure-function analysis of Sua5 (-Sua5). Crystallographic data revealed binding sites for bicarbonate substrate and pyrophosphate product. The linker of -Sua5 forms a loop structure that folds into the active site gorge and closes it. Using structure-guided mutational analysis, we established that the conserved sequence motifs in the linker and the domain-domain interface are essential for the function of -Sua5. We propose that the linker participates actively in the biosynthesis of TC-AMP by binding to ATP/PPi and by stabilizing the -carboxy-l-threonine intermediate. Hence, TsaC orthologs which lack such a linker and SUA5 domain use a different mechanism for TC-AMP synthesis.

PubMed: 29650678
DOI: 10.1261/rna.066092.118

実験手法

X-RAY DIFFRACTION (2.62 Å)