3VSC

Crystal Structure of the K127A Mutant of O-Phosphoserine Sulfhydrylase Complexed with External Schiff Base of Pyridoxal 5'-Phosphate with O-Phospho-L-Serine

3VSC の概要

• エントリーDOI: 10.2210/pdb3vsc/pdb
• 関連するPDBエントリー: 1wkv 3vsa 3vsd
• 分子名称: Protein CysO, PYRIDOXAL-5'-PHOSPHATE, PHOSPHOSERINE, ... (5 entities in total)
• 機能のキーワード: cysteine biosynthesis, external schiff base of plp with o-phosphoserine, k127a mutant, sulfhydrylase (inactivated), transferase
• 由来する生物種: Aeropyrum pernix
• タンパク質・核酸の鎖数: 2
• 化学式量合計: 84918.11

構造登録者

Nakamura, T.,Kawai, Y.,Kataoka, M.,Ishikawa, K. (登録日: 2012-04-24, 公開日: 2012-05-16, 最終更新日: 2025-03-26)

主引用文献

Nakamura, T.,Kawai, Y.,Kunimoto, K.,Iwasaki, Y.,Nishii, K.,Kataoka, M.,Ishikawa, K.
Structural analysis of the substrate recognition mechanism in O-phosphoserine sulfhydrylase from the hyperthermophilic archaeon Aeropyrum pernix K1
J.Mol.Biol., 422:33-44, 2012

PubMed Abstract: L-Cysteine is synthesized from O-acetyl-L-serine (OAS) and sulfide by O-acetylserine sulfhydrylase (OASS; EC 2.5.1.47) in plants and bacteria. O-phosphoserine sulfhydrylase (OPSS; EC 2.5.1.65) is a novel enzyme from the hyperthermophilic aerobic archaeon Aeropyrum pernix K1 (2003). OPSS can use OAS or O-phospho-L-serine (OPS) to synthesize L-cysteine. To elucidate the mechanism of the substrate specificity of OPSS, we analyzed three-dimensional structures of the active site of the enzyme. The active-site lysine (K127) of OPSS forms an internal Schiff base with pyridoxal 5'-phosphate. Therefore, crystals of the complexes formed by the K127A mutant with the external Schiff base of pyridoxal 5'-phosphate with either OPS or OAS were prepared and examined by X-ray diffraction analysis. In contrast to that observed for OASS, no significant difference was seen in the overall structure between the free and complexed forms of OPSS. The side chains of T152, S153, and Q224 interacted with the carboxylate of the substrates, as a previous study has suggested. The side chain of R297 has been proposed to recognize the phosphate group of OPS. Surprisingly, however, the position of R297 was significantly unchanged in the complex of the OPSS K127A mutant with the external Schiff base, allowing enough space for an interaction with OPS. The positively charged environment around the entrance of the active site including S153 and R297 is important for accepting negatively charged substrates such as OPS.

PubMed: 22580223
DOI: 10.1016/j.jmb.2012.05.009

実験手法

X-RAY DIFFRACTION (2.07 Å)