5BWD

Benzylsuccinate alpha-gamma bound to fumarate

5BWD の概要

• エントリーDOI: 10.2210/pdb5bwd/pdb
• 関連するPDBエントリー: 4PKC 5BWE
• 分子名称: benzylsuccinate synthase alpha chain, benzylsuccinate synthase gamma chain, FUMARIC ACID, ... (7 entities in total)
• 機能のキーワード: complex, radical, disorder, lyase
• 由来する生物種: Thauera aromatica; 詳細
• タンパク質・核酸の鎖数: 2
• 化学式量合計: 107166.10

構造登録者

Funk, M.A.,Drennan, C.L. (登録日: 2015-06-07, 公開日: 2015-08-05, 最終更新日: 2023-11-15)

主引用文献

Funk, M.A.,Marsh, E.N.,Drennan, C.L.
Substrate-bound Structures of Benzylsuccinate Synthase Reveal How Toluene Is Activated in Anaerobic Hydrocarbon Degradation.
J.Biol.Chem., 290:22398-22408, 2015

PubMed Abstract: Various bacteria perform anaerobic degradation of small hydrocarbons as a source of energy and cellular carbon. To activate non-reactive hydrocarbons such as toluene, enzymes conjugate these molecules to fumarate in a radical-catalyzed, C-C bond-forming reaction. We have determined x-ray crystal structures of the glycyl radical enzyme that catalyzes the addition of toluene to fumarate, benzylsuccinate synthase (BSS), in two oligomeric states with fumarate alone or with both substrates. We find that fumarate is secured at the bottom of a long active site cavity with toluene bound directly above it. The two substrates adopt orientations that appear ideal for radical-mediated C-C bond formation; the methyl group of toluene is positioned between fumarate and a cysteine that forms a thiyl radical during catalysis, which is in turn adjacent to the glycine that serves as a radical storage residue. Toluene is held in place by fumarate on one face and tight packing by hydrophobic residues on the other face and sides. These hydrophobic residues appear to become ordered, thus encapsulating toluene, only in the presence of BSSβ, a small protein subunit that forms a tight complex with BSSα, the catalytic subunit. Enzymes related to BSS are able to metabolize a wide range of hydrocarbons through attachment to fumarate. Using our structures as a guide, we have constructed homology models of several of these "X-succinate synthases" and determined conservation patterns that will be useful in understanding the basis for catalysis and specificity in this family of enzymes.

PubMed: 26224635
DOI: 10.1074/jbc.M115.670737

実験手法

X-RAY DIFFRACTION (2 Å)