5LSR

Carboxysome shell protein CcmP from Synechococcus elongatus PCC 7942

5LSR の概要

• エントリーDOI: 10.2210/pdb5lsr/pdb
• 分子名称: CcmP, THIOCYANATE ION (3 entities in total)
• 機能のキーワード: carboxysome shell protein bmc domain gated transport, transport protein
• 由来する生物種: Synechococcus elongatus PCC 7942
• タンパク質・核酸の鎖数: 3
• 化学式量合計: 72931.10

構造登録者

Larsson, A.M.,Hasse, D.,Valegard, K.,Andersson, I. (登録日: 2016-09-05, 公開日: 2017-04-12, 最終更新日: 2024-01-17)

主引用文献

Larsson, A.M.,Hasse, D.,Valegard, K.,Andersson, I.
Crystal structures of beta-carboxysome shell protein CcmP: ligand binding correlates with the closed or open central pore.
J. Exp. Bot., 68:3857-3867, 2017

PubMed Abstract: Cyanobacterial CO2 fixation is promoted by encapsulating and co-localizing the CO2-fixing enzymes within a protein shell, the carboxysome. A key feature of the carboxysome is its ability to control selectively the flux of metabolites in and out of the shell. The β-carboxysome shell protein CcmP has been shown to form a double layer of pseudohexamers with a relatively large central pore (~13 Å diameter), which may allow passage of larger metabolites such as the substrate for CO2 fixation, ribulose 1,5-bisphosphate, through the shell. Here we describe two crystal structures, at 1.45 Å and 1.65 Å resolution, of CcmP from Synechococcus elongatus PCC7942 (SeCcmP). The central pore of CcmP is open or closed at its ends, depending on the conformation of two conserved residues, Glu69 and Arg70. The presence of glycerol resulted in a pore that is open at one end and closed at the opposite end. When glycerol was omitted, both ends of the barrel became closed. A binding pocket at the interior of the barrel featured residual density with distinct differences in size and shape depending on the conformation, open or closed, of the central pore of SeCcmP, suggestive of a metabolite-driven mechanism for the gating of the pore.

PubMed: 28369612
DOI: 10.1093/jxb/erx070

実験手法

X-RAY DIFFRACTION (1.65 Å)