6HUL

Sulfolobus solfataricus Tryptophan Synthase AB Complex

6HUL の概要

• エントリーDOI: 10.2210/pdb6hul/pdb
• 分子名称: Tryptophan synthase alpha chain, Tryptophan synthase beta chain 1, SN-GLYCEROL-3-PHOSPHATE, ... (8 entities in total)
• 機能のキーワード: tryptophan synthase plp, lyase
• 由来する生物種: Sulfolobus solfataricus; 詳細
• タンパク質・核酸の鎖数: 2
• 化学式量合計: 75759.51

構造登録者

Fleming, J.R.,Mayans, O. (登録日: 2018-10-08, 公開日: 2018-11-07, 最終更新日: 2024-01-24)

主引用文献

Fleming, J.R.,Schupfner, M.,Busch, F.,Basle, A.,Ehrmann, A.,Sterner, R.,Mayans, O.
Evolutionary Morphing of Tryptophan Synthase: Functional Mechanisms for the Enzymatic Channeling of Indole.
J.Mol.Biol., 430:5066-5079, 2018

PubMed Abstract: Tryptophan synthase (TrpS) is a heterotetrameric αββα enzyme that exhibits complex substrate channeling and allosteric mechanisms and is a model system in enzymology. In this work, we characterize proposed early and late evolutionary states of TrpS and show that they have distinct quaternary structures caused by insertions-deletions of sequence segments (indels) in the β-subunit. Remarkably, indole hydrophobic channels that connect α and β active sites have re-emerged in both TrpS types, yet they follow different paths through the β-subunit fold. Also, both TrpS geometries activate the α-subunit through the rearrangement of loops flanking the active site. Our results link evolutionary sequence changes in the enzyme subunits with channeling and allostery in the TrpS enzymes. The findings demonstrate that indels allow protein quaternary architectures to escape "minima" in the evolutionary landscape, thereby overcoming the conservational constraints imposed by existing functional interfaces and being free to morph into new mechanistic enzymes.

PubMed: 30367843
DOI: 10.1016/j.jmb.2018.10.013

実験手法

X-RAY DIFFRACTION (2.55 Å)