1MUM

Structure of the 2-Methylisocitrate Lyase (PrpB) from Escherichia coli

1MUM の概要

• エントリーDOI: 10.2210/pdb1mum/pdb
• 分子名称: 2-methylisocitrate lyase, MAGNESIUM ION (3 entities in total)
• 機能のキーワード: prpb, lyase, methylisocitrate, methylcitrate cycle, tim-barrel
• 由来する生物種: Escherichia coli
• タンパク質・核酸の鎖数: 2
• 化学式量合計: 64125.45

構造登録者

Grimm, C.,Reuter, K. (登録日: 2002-09-24, 公開日: 2003-04-29, 最終更新日: 2024-03-13)

主引用文献

Grimm, C.,Evers, A.,Brock, M.,Maerker, C.,Klebe, G.,Buckel, W.,Reuter, K.
Crystal structure of 2-methylisocitrate lyase (PrpB) from Escherichia coli and modelling of its ligand bound active centre.
J.Mol.Biol., 328:609-621, 2003

PubMed Abstract: Following acetate, propionate is the second most abundant low molecular mass carbon compound found in soil. Many microorganisms, including most, if not all fungi, as well as several aerobic bacteria, such as Escherichia coli and Salmonella enterica oxidize propionate via the methylcitrate cycle. The enzyme 2-methylisocitrate lyase (PrpB) from Escherichia coli catalysing the last step of this cycle, the cleavage of 2-methylisocitrate to pyruvate and succinate, was crystallised and its structure determined to a resolution of 1.9A. The enzyme, which strictly depends on Mg(2+) for catalysis, belongs to the isocitrate lyase protein family. A common feature of members of this enzyme family is the movement of a so-called "active site loop" from an open into a closed conformation upon substrate binding thus shielding the reactants from the surrounding solvent. Since in the presented structure, PrpB contains, apart from a Mg(2+), no ligand, the active site loop is found in an open conformation. This conformation, however, differs significantly from the open conformation present in the so far known structures of ligand-free isocitrate lyases. A possible impact of this observation with respect to the different responses of isocitrate lyases and PrpB upon treatment with the common inhibitor 3-bromopyruvate is discussed. Based on the structure of ligand-bound isocitrate lyase from Mycobacterium tuberculosis a model of the substrate-bound PrpB enzyme in its closed conformation was created which provides hints towards the substrate specificity of this enzyme.

PubMed: 12706720
DOI: 10.1016/S0022-2836(03)00358-9

実験手法

X-RAY DIFFRACTION (1.9 Å)