2AEV

MJ0158, NaBH4-reduced form

2AEV の概要

• エントリーDOI: 10.2210/pdb2aev/pdb
• 関連するPDBエントリー: 2AEV
• 分子名称: Hypothetical protein MJ0158, SULFATE ION (3 entities in total)
• 機能のキーワード: selenocysteine synthase, plp, pyridoxal phosphate, homo-oligomerization, unknown function
• 由来する生物種: Methanocaldococcus jannaschii
• タンパク質・核酸の鎖数: 1
• 化学式量合計: 43035.44

構造登録者

Kaiser, J.T.,Gromadski, K.,Rother, M.,Engelhardt, H.,Rodnina, M.V.,Wahl, M.C. (登録日: 2005-07-24, 公開日: 2005-10-04, 最終更新日: 2023-11-15)

主引用文献

Kaiser, J.T.,Gromadski, K.,Rother, M.,Engelhardt, H.,Rodnina, M.V.,Wahl, M.C.
Structural and functional investigation of a putative archaeal selenocysteine synthase
Biochemistry, 44:13315-13327, 2005

PubMed Abstract: Bacterial selenocysteine synthase converts seryl-tRNA(Sec) to selenocysteinyl-tRNA(Sec) for selenoprotein biosynthesis. The identity of this enzyme in archaea and eukaryotes is unknown. On the basis of sequence similarity, a conserved open reading frame has been annotated as a selenocysteine synthase gene in archaeal genomes. We have determined the crystal structure of the corresponding protein from Methanococcus jannaschii, MJ0158. The protein was found to be dimeric with a distinctive domain arrangement and an exposed active site, built from residues of the large domain of one protomer alone. The shape of the dimer is reminiscent of a substructure of the decameric Escherichia coli selenocysteine synthase seen in electron microscopic projections. However, biochemical analyses demonstrated that MJ0158 lacked affinity for E. coli seryl-tRNA(Sec) or M. jannaschii seryl-tRNA(Sec), and neither substrate was directly converted to selenocysteinyl-tRNA(Sec) by MJ0158 when supplied with selenophosphate. We then tested a hypothetical M. jannaschii O-phosphoseryl-tRNA(Sec) kinase and demonstrated that the enzyme converts seryl-tRNA(Sec) to O-phosphoseryl-tRNA(Sec) that could constitute an activated intermediate for selenocysteinyl-tRNA(Sec) production. MJ0158 also failed to convert O-phosphoseryl-tRNA(Sec) to selenocysteinyl-tRNA(Sec). In contrast, both archaeal and bacterial seryl-tRNA synthetases were able to charge both archaeal and bacterial tRNA(Sec) with serine, and E. coli selenocysteine synthase converted both types of seryl-tRNA(Sec) to selenocysteinyl-tRNA(Sec). These findings demonstrate that a number of factors from the selenoprotein biosynthesis machineries are cross-reactive between the bacterial and the archaeal systems but that MJ0158 either does not encode a selenocysteine synthase or requires additional factors for activity.

PubMed: 16201757
DOI: 10.1021/bi051110r

実験手法

X-RAY DIFFRACTION (2 Å)