1LON

Crystal Structure of the Recombinant Mouse-Muscle Adenylosuccinate Synthetase Complexed with 6-phosphoryl-IMP, GDP and Hadacidin

1LON の概要

• エントリーDOI: 10.2210/pdb1lon/pdb
• 関連するPDBエントリー: 1IWE 1J4B 1LNY 1LOO
• 分子名称: adenylosuccinate synthetase, MAGNESIUM ION, 6-O-PHOSPHORYL INOSINE MONOPHOSPHATE, ... (6 entities in total)
• 機能のキーワード: purine biosynthesis, ligase, gtp-binding
• 由来する生物種: Mus musculus (house mouse)
• 細胞内の位置: Cytoplasm: P28650
• タンパク質・核酸の鎖数: 1
• 化学式量合計: 51336.07

構造登録者

Iancu, C.V.,Borza, T.,Fromm, H.J.,Honzatko, R.B. (登録日: 2002-05-06, 公開日: 2002-08-28, 最終更新日: 2023-10-25)

主引用文献

Iancu, C.V.,Borza, T.,Fromm, H.J.,Honzatko, R.B.
IMP, GTP, and 6-phosphoryl-IMP complexes of recombinant mouse muscle adenylosuccinate synthetase.
J.Biol.Chem., 277:26779-26787, 2002

PubMed Abstract: Prokaryotes have a single form of adenylosuccinate synthetase that controls the committed step of AMP biosynthesis, but vertebrates have two isozymes of the synthetase. The basic isozyme, which predominates in muscle, participates in the purine nucleotide cycle, has an active site conformation different from that of the Escherichia coli enzyme, and exhibits significant differences in ligand recognition. Crystalline complexes presented here of the recombinant basic isozyme from mouse show the following. GTP alone binds to the active site without inducing a conformational change. IMP in combination with an acetate anion induces major conformational changes and organizes the active site for catalysis. IMP, in the absence of GTP, binds to the GTP pocket of the synthetase. The combination of GTP and IMP results in the formation of a stable complex of 6-phosphoryl-IMP and GDP in the presence or absence of hadacidin. The response of the basic isozyme to GTP alone differs from that of synthetases from plants, and yet the conformation of the mouse basic and E. coli synthetases in their complexes with GDP, 6-phosphoryl-IMP, and hadacidin are nearly identical. Hence, reported differences in ligand recognition among synthetases probably arise from conformational variations observed in partially ligated enzymes.

PubMed: 12004071
DOI: 10.1074/jbc.M203730200

実験手法

X-RAY DIFFRACTION (2.1 Å)