1I2D

CRYSTAL STRUCTURE OF ATP SULFURYLASE FROM PENICILLIUM CHRYSOGENUM

1I2D の概要

• エントリーDOI: 10.2210/pdb1i2d/pdb
• 分子名称: ATP SULFURYLASE, ADENOSINE-5'-PHOSPHOSULFATE (3 entities in total)
• 機能のキーワード: nucleotide binding, allosteric, hexamer, transferase
• 由来する生物種: Penicillium chrysogenum
• 細胞内の位置: Cytoplasm (By similarity): Q12650
• タンパク質・核酸の鎖数: 3
• 化学式量合計: 194709.11

構造登録者

MacRae, I.J.,Segel, I.H.,Fisher, A.J. (登録日: 2001-02-07, 公開日: 2001-07-11, 最終更新日: 2024-02-07)

主引用文献

MacRae, I.J.,Segel, I.H.,Fisher, A.J.
Crystal structure of ATP sulfurylase from Penicillium chrysogenum: insights into the allosteric regulation of sulfate assimilation.
Biochemistry, 40:6795-6804, 2001

PubMed Abstract: ATP sulfurylase from Penicillium chrysogenum is an allosterically regulated enzyme composed of six identical 63.7 kDa subunits (573 residues). The C-terminal allosteric domain of each subunit is homologous to APS kinase. In the presence of APS, the enzyme crystallized in the orthorhombic space group (I222) with unit cell parameters of a = 135.7 A, b = 162.1 A, and c = 273.0 A. The X-ray structure at 2.8 A resolution established that the hexameric enzyme is a dimer of triads in the shape of an oblate ellipsoid 140 A diameter x 70 A. Each subunit is divided into a discreet N-terminal domain, a central catalytic domain, and a C-terminal allosteric domain. Two molecules of APS bound per subunit clearly identify the catalytic and allosteric domains. The sequence 197QXRN200 is largely responsible for anchoring the phosphosulfate group of APS at the active site of the catalytic domain. The specificity of the catalytic site for adenine nucleotides is established by specific hydrogen bonds to the protein main chain. APS was bound to the allosteric site through sequence-specific interactions with amino acid side chains that are conserved in true APS kinase. Within a given triad, the allosteric domain of one subunit interacts with the catalytic domain of another. There are also allosteric-allosteric, allosteric-N-terminal, and catalytic-catalytic domain interactions across the triad interface. The overall interactions-each subunit with four others-provide stability to the hexamer as well as a way to propagate a concerted allosteric transition. The structure presented here is believed to be the R state. A solvent channel, 15-70 A wide exists along the 3-fold axis, but substrates have access to the catalytic site only from the external medium. On the other hand, a surface "trench" links each catalytic site in one triad with an allosteric site in the other triad. This trench may be a vestigial feature of a bifunctional ("PAPS synthetase") ancestor of fungal ATP sulfurylase.

PubMed: 11389593
DOI: 10.1021/bi010367w

実験手法

X-RAY DIFFRACTION (2.81 Å)