3WKR

Crystal structure of the SepCysS-SepCysE complex from Methanocaldococcus jannaschii

3WKR の概要

• エントリーDOI: 10.2210/pdb3wkr/pdb
• 分子名称: O-phospho-L-seryl-tRNA:Cys-tRNA synthase, Uncharacterized protein MJ1481 (3 entities in total)
• 機能のキーワード: aminoacyl trna synthesis, transferase
• 由来する生物種: Methanocaldococcus jannaschii; 詳細
• タンパク質・核酸の鎖数: 8
• 化学式量合計: 291036.44

構造登録者

Nakazawa, Y.,Asano, N.,Nakamura, A.,Yao, M. (登録日: 2013-10-30, 公開日: 2014-07-16, 最終更新日: 2022-08-24)

主引用文献

Liu, Y.,Nakamura, A.,Nakazawa, Y.,Asano, N.,Ford, K.A.,Hohn, M.J.,Tanaka, I.,Yao, M.,Soll, D.
Ancient translation factor is essential for tRNA-dependent cysteine biosynthesis in methanogenic archaea.
Proc.Natl.Acad.Sci.USA, 111:10520-10525, 2014

PubMed Abstract: Methanogenic archaea lack cysteinyl-tRNA synthetase; they synthesize Cys-tRNA and cysteine in a tRNA-dependent manner. Two enzymes are required: Phosphoseryl-tRNA synthetase (SepRS) forms phosphoseryl-tRNA(Cys) (Sep-tRNA(Cys)), which is converted to Cys-tRNA(Cys) by Sep-tRNA:Cys-tRNA synthase (SepCysS). This represents the ancestral pathway of Cys biosynthesis and coding in archaea. Here we report a translation factor, SepCysE, essential for methanococcal Cys biosynthesis; its deletion in Methanococcus maripaludis causes Cys auxotrophy. SepCysE acts as a scaffold for SepRS and SepCysS to form a stable high-affinity complex for tRNA(Cys) causing a 14-fold increase in the initial rate of Cys-tRNA(Cys) formation. Based on our crystal structure (2.8-Å resolution) of a SepCysS⋅SepCysE complex, a SepRS⋅SepCysE⋅SepCysS structure model suggests that this ternary complex enables substrate channeling of Sep-tRNA(Cys). A phylogenetic analysis suggests coevolution of SepCysE with SepRS and SepCysS in the last universal common ancestral state. Our findings suggest that the tRNA-dependent Cys biosynthesis proceeds in a multienzyme complex without release of the intermediate and this mechanism may have facilitated the addition of Cys to the genetic code.

PubMed: 25002468
DOI: 10.1073/pnas.1411267111

実験手法

X-RAY DIFFRACTION (2.803 Å)