6CVA

Crystal structure of the N. meningitides methionine-binding protein in its substrate-free conformation

6CVA の概要

• エントリーDOI: 10.2210/pdb6cva/pdb
• 分子名称: Lipoprotein (2 entities in total)
• 機能のキーワード: substrate-binding protein, protein binding
• 由来する生物種: Neisseria meningitidis
• タンパク質・核酸の鎖数: 1
• 化学式量合計: 26985.93

構造登録者

Nguyen, P.T.,Lai, J.Y.,Kaiser, J.T.,Rees, D.C. (登録日: 2018-03-27, 公開日: 2019-04-03, 最終更新日: 2024-10-09)

主引用文献

Nguyen, P.T.,Lai, J.Y.,Kaiser, J.T.,Rees, D.C.
Structures of the Neisseria meningitides methionine-binding protein MetQ in substrate-free form and bound to l- and d-methionine isomers.
Protein Sci., 28:1750-1757, 2019

PubMed Abstract: The bacterial periplasmic methionine-binding protein MetQ is involved in the import of methionine by the cognate MetNI methionine ATP binding cassette (ABC) transporter. The MetNIQ system is one of the few members of the ABC importer family that has been structurally characterized in multiple conformational states. Critical missing elements in the structural analysis of MetNIQ are the structure of the substrate-free form of MetQ, and detailing how MetQ binds multiple methionine derivatives, including both l- and d-methionine isomers. In this study, we report the structures of the Neisseria meningitides MetQ in substrate-free form and in complexes with l-methionine and with d-methionine, along with the associated binding constants determined by isothermal titration calorimetry. Structures of the substrate-free (N238A) and substrate-bound N. meningitides MetQ are related by a "Venus-fly trap" hinge-type movement of the two domains accompanying methionine binding and dissociation. l- and d-methionine bind to the same site on MetQ, and this study emphasizes the important role of asparagine 238 in ligand binding and affinity. A thermodynamic analysis demonstrates that ligand-free MetQ associates with the ATP-bound form of MetNI ∼40 times more tightly than does liganded MetQ, consistent with the necessity of dissociating methionine from MetQ for transport to occur.

PubMed: 31348565
DOI: 10.1002/pro.3694

実験手法

X-RAY DIFFRACTION (1.559 Å)