4RI3

Crystal structure of DCCD-modified PsbS from spinach

Summary for 4RI3

• Entry DOI: 10.2210/pdb4ri3/pdb
• Related: 4RI2
• Descriptor: Photosystem II 22 kDa protein, chloroplastic, DICYCLOHEXYLUREA, nonyl beta-D-glucopyranoside, ... (5 entities in total)
• Functional Keywords: transmembrane helices, photo protection, dccd-modified, membrane protein
• Biological source: Spinacia oleracea (Spinach)
• Cellular location: Plastid, chloroplast thylakoid membrane; Multi-pass membrane protein: Q02060
• Total number of polymer chains: 2
• Total formula weight: 48174.84

Authors

Fan, M.,Li, M.,Chang, W. (deposition date: 2014-10-05, release date: 2015-08-12, Last modification date: 2020-07-29)

Primary citation

Fan, M.,Li, M.,Liu, Z.,Cao, P.,Pan, X.,Zhang, H.,Zhao, X.,Zhang, J.,Chang, W.
Crystal structures of the PsbS protein essential for photoprotection in plants.
Nat.Struct.Mol.Biol., 22:729-735, 2015

PubMed Abstract: The photosystem II protein PsbS has an essential role in qE-type nonphotochemical quenching, which protects plants from photodamage under excess light conditions. qE is initiated by activation of PsbS by low pH, but the mechanism of PsbS action remains elusive. Here we report the low-pH crystal structures of PsbS from spinach in its free form and in complex with the qE inhibitor N,N'-dicyclohexylcarbodiimide (DCCD), revealing that PsbS adopts a unique folding pattern, and, unlike other members of the light-harvesting-complex superfamily, it is a noncanonical pigment-binding protein. Structural and biochemical evidence shows that both active and inactive PsbS form homodimers in the thylakoid membranes, and DCCD binding disrupts the lumenal intermolecular hydrogen bonds of the active PsbS dimer. Activation of PsbS by low pH during qE may involve a conformational change associated with altered lumenal intermolecular interactions of the PsbS dimer.

PubMed: 26258636
DOI: 10.1038/nsmb.3068

Experimental method

X-RAY DIFFRACTION (2.7 Å)