4YKK

Mnemiopsis leidyi ML032222a iGluR LBD D-serine complex

4YKK の概要

• エントリーDOI: 10.2210/pdb4ykk/pdb
• 関連するPDBエントリー: 4YKI 4YKJ 4YKP 4YKV
• 分子名称: ML032222a iGluR, MAGNESIUM ION, D-SERINE, ... (5 entities in total)
• 機能のキーワード: membrane protein, glutamate receptor, ion channel
• 由来する生物種: Mnemiopsis leidyi
• タンパク質・核酸の鎖数: 2
• 化学式量合計: 58307.74

構造登録者

Alberstein, R.G.,Mayer, M.L. (登録日: 2015-03-04, 公開日: 2015-10-21, 最終更新日: 2024-11-20)

主引用文献

Alberstein, R.,Grey, R.,Zimmet, A.,Simmons, D.K.,Mayer, M.L.
Glycine activated ion channel subunits encoded by ctenophore glutamate receptor genes.
Proc.Natl.Acad.Sci.USA, 112:E6048-E6057, 2015

PubMed Abstract: Recent genome projects for ctenophores have revealed the presence of numerous ionotropic glutamate receptors (iGluRs) in Mnemiopsis leidyi and Pleurobrachia bachei, among our earliest metazoan ancestors. Sequence alignments and phylogenetic analysis show that these form a distinct clade from the well-characterized AMPA, kainate, and NMDA iGluR subtypes found in vertebrates. Although annotated as glutamate and kainate receptors, crystal structures of the ML032222a and PbiGluR3 ligand-binding domains (LBDs) reveal endogenous glycine in the binding pocket, whereas ligand-binding assays show that glycine binds with nanomolar affinity; biochemical assays and structural analysis establish that glutamate is occluded from the binding cavity. Further analysis reveals ctenophore-specific features, such as an interdomain Arg-Glu salt bridge, present only in subunits that bind glycine, but also a conserved disulfide in loop 1 of the LBD that is found in all vertebrate NMDA but not AMPA or kainate receptors. We hypothesize that ctenophore iGluRs are related to an early ancestor of NMDA receptors, suggesting a common evolutionary path for ctenophores and bilaterian species, and suggest that future work should consider both glycine and glutamate as candidate neurotransmitters in ctenophore species.

PubMed: 26460032
DOI: 10.1073/pnas.1513771112

実験手法

X-RAY DIFFRACTION (1.38 Å)