1ECX

NIFS-LIKE PROTEIN

1ECX の概要

• エントリーDOI: 10.2210/pdb1ecx/pdb
• 関連するPDBエントリー: 1EG5
• 分子名称: AMINOTRANSFERASE, PYRIDOXAL-5'-PHOSPHATE, CYSTEINE, ... (4 entities in total)
• 機能のキーワード: plp-dependent enzymes, iron-sulfur-cluster synthesis, c-s beta lyase, transferase
• 由来する生物種: Thermotoga maritima
• タンパク質・核酸の鎖数: 2
• 化学式量合計: 86599.66

構造登録者

Kaiser, J.T.,Clausen, T.C.,Bourenkow, G.P.,Bartunik, H.-D.,Steinbacher, S.,Huber, R. (登録日: 2000-01-26, 公開日: 2000-03-20, 最終更新日: 2024-02-07)

主引用文献

Kaiser, J.T.,Clausen, T.,Bourenkow, G.P.,Bartunik, H.D.,Steinbacher, S.,Huber, R.
Crystal structure of a NifS-like protein from Thermotoga maritima: implications for iron sulphur cluster assembly.
J.Mol.Biol., 297:451-464, 2000

PubMed Abstract: NifS-like proteins are ubiquitous, homodimeric, proteins which belong to the alpha-family of pyridoxal-5'-phoshate dependent enzymes. They are proposed to donate elementary sulphur, generated from cysteine, via a cysteinepersulphide intermediate during iron sulphur cluster biosynthesis, an important albeit not well understood process. Here, we report on the crystal structure of a NifS-like protein from the hyperthermophilic bacterium Thermotoga maritima (tmNifS) at 2.0 A resolution. The tmNifS is structured into two domains, the larger bearing the pyridoxal-5'-phosphate-binding active site, the smaller hosting the active site cysteine in the middle of a highly flexible loop, 12 amino acid residues in length. Once charged with sulphur the loop could possibly deliver S(0) directly to regions far remote from the protein. Based on the three-dimensional structures of the native as well as the substrate complexed form and on spectrophotometric results, a mechanism of sulphur activation is proposed. The His99, which stacks on top of the pyridoxal-5'-phosphate co-factor, is assigned a crucial role during the catalytic cycle by acting as an acid-base catalyst and is believed to have a pK(a) value depending on the co-factor redox state.

PubMed: 10715213
DOI: 10.1006/jmbi.2000.3581

実験手法

X-RAY DIFFRACTION (2.7 Å)