9FRX

Porcine Retinol-Binding Protein 3 (RBP3)

9FRX の概要

• エントリーDOI: 10.2210/pdb9frx/pdb
• EMDBエントリー: 50552
• 分子名称: Retinol binding protein 3 (1 entity in total)
• 機能のキーワード: retinoids; interphotoreceptor matrix (ipm); visual cycle; shuttle;, transport protein
• 由来する生物種: Sus scrofa (pig)
• タンパク質・核酸の鎖数: 1
• 化学式量合計: 138621.63

構造登録者

Kaushik, V.,Gessa, L.,Kumar, N.,Pinkas, M.,Czarnocki-Cieciura, M.,Palczewski, K.,Novacek, J.,Fernandes, H. (登録日: 2024-06-19, 公開日: 2025-02-05, 最終更新日: 2025-07-02)

主引用文献

Kaushik, V.,Gessa, L.,Kumar, N.,Pinkas, M.,Czarnocki-Cieciura, M.,Palczewski, K.,Novacek, J.,Fernandes, H.
CryoEM structure and small-angle X-ray scattering analyses of porcine retinol-binding protein 3.
Open Biology, 15:240180-240180, 2025

PubMed Abstract: The vertebrate visual cycle hinges on enzymatically converting all--retinol (at-ROL) into 11--retinal (11c-RAL), the chromophore that binds to opsins in photoreceptors, forming light-responsive pigments. When struck by a photon, these pigments activate the phototransduction pathway and initiate the process of vision. The enzymatic isomerization of at-ROL, crucial for restoring the visual pigments and preparing them to receive new light stimuli, relies on various enzymes found in both the photoreceptors and retinal pigment epithelium cells. To function effectively, retinoids must shuttle between these two cell types. Retinol-binding protein 3 (RBP3), located in the interphotoreceptor matrix, probably plays a pivotal role in this transport mechanism. Comprised of four retinoid-binding modules, RBP3 also binds fatty acids, potentially aiding retinal function by facilitating the loading and unloading of different retinoids at specific cell types thereby directing the cycle. In this study, we present a 3.67 Å cryoEM structure of porcine RBP3, along with molecular docking analysis and corroborative in-solution small-angle X-ray scattering data for titration of RBP3 with relevant ligands, that also give insights on RBP3 conformational adaptability.

PubMed: 39837501
DOI: 10.1098/rsob.240180

実験手法

ELECTRON MICROSCOPY (3.67 Å)