2B99

Crystal Structure of an archaeal pentameric riboflavin synthase Complex with a Substrate analog inhibitor

2B99 の概要

• エントリーDOI: 10.2210/pdb2b99/pdb
• 分子名称: Riboflavin synthase, 6,7-DIOXO-5H-8-RIBITYLAMINOLUMAZINE (3 entities in total)
• 機能のキーワード: lumazine riboflavin, transferase
• 由来する生物種: Methanocaldococcus jannaschii
• タンパク質・核酸の鎖数: 5
• 化学式量合計: 90925.46

構造登録者

Ramsperger, A.,Augustin, M.,Schott, A.K.,Gerhardt, S.,Krojer, T.,Eisenreich, W.,Illarionov, B.,Cushman, M.,Bacher, A.,Huber, R.,Fischer, M. (登録日: 2005-10-11, 公開日: 2005-11-08, 最終更新日: 2024-02-14)

主引用文献

Ramsperger, A.,Augustin, M.,Schott, A.K.,Gerhardt, S.,Krojer, T.,Eisenreich, W.,Illarionov, B.,Cushman, M.,Bacher, A.,Huber, R.,Fischer, M.
Crystal Structure of an Archaeal Pentameric Riboflavin Synthase in Complex with a Substrate Analog Inhibitor: stereochemical implications
J.Biol.Chem., 281:1224-1232, 2006

PubMed Abstract: Whereas eubacterial and eukaryotic riboflavin synthases form homotrimers, archaeal riboflavin synthases from Methanocaldococcus jannaschii and Methanothermobacter thermoautrophicus are homopentamers with sequence similarity to the 6,7-dimethyl-8-ribityllumazine synthase catalyzing the penultimate step in riboflavin biosynthesis. Recently it could be shown that the complex dismutation reaction catalyzed by the pentameric M. jannaschii riboflavin synthase generates riboflavin with the same regiochemistry as observed for trimeric riboflavin synthases. Here we present crystal structures of the pentameric riboflavin synthase from M. jannaschii and its complex with the substrate analog inhibitor, 6,7-dioxo-8-ribityllumazine. The complex structure shows five active sites located between adjacent monomers of the pentamer. Each active site can accommodate two substrate analog molecules in anti-parallel orientation. The topology of the two bound ligands at the active site is well in line with the known stereochemistry of a pentacyclic adduct of 6,7-dimethyl-8-ribityllumazine that has been shown to serve as a kinetically competent intermediate. The pentacyclic intermediates of trimeric and pentameric riboflavin synthases are diastereomers.

PubMed: 16272154
DOI: 10.1074/jbc.M509440200

実験手法

X-RAY DIFFRACTION (2.22 Å)