4K7B

Crystal structure of Extrinsic protein in photosystem II

Summary for 4K7B

• Entry DOI: 10.2210/pdb4k7b/pdb
• Descriptor: Extrinsic protein in photosystem II, SULFATE ION, GLYCEROL, ... (4 entities in total)
• Functional Keywords: photosynthesis
• Biological source: Chaetoceros gracilis
• Total number of polymer chains: 1
• Total formula weight: 13558.08

Authors

Nagao, R.,Suga, M.,Niikura, A.,Okumura, A.,Koua, F.H.M.,Suzuki, T.,Tomo, T.,Enami, I.,Shen, J.R. (deposition date: 2013-04-16, release date: 2013-09-18, Last modification date: 2024-03-20)

Primary citation

Nagao, R.,Suga, M.,Niikura, A.,Okumura, A.,Koua, F.H.,Suzuki, T.,Tomo, T.,Enami, I.,Shen, J.R.
Crystal Structure of Psb31, a Novel Extrinsic Protein of Photosystem II from a Marine Centric Diatom and Implications for Its Binding and Function
Biochemistry, 52:6646-6652, 2013

PubMed Abstract: Psb31 is a fifth extrinsic protein found in photosystem II (PSII) of a centric diatom, Chaetoceros gracilis . The protein has been shown to bind directly to PSII in the absence of other extrinsic proteins and serves in part as a substitute for PsbO in supporting oxygen evolution. We report here the crystal structure of Psb31 at a resolution of 1.55 Å. The structure of Psb31 was composed of two domains, one major, N-terminal four helical domain and one minor, flexible C-terminal domain. The four helices in the N-terminal domain were arranged in an up-down-up-down fold, which appeared unexpectedly to be similar to the structure of spinach PsbQ, in spite of their low sequence homology. This suggests that the centric diatom PSII contains another PsbQ-type extrinsic protein in addition to the original PsbQ protein found in the organism. On the other hand, the C-terminal domain of Psb31 has a unique structure composed of one loop and one short helix. Based on these structural analysis and chemical cross-linking experiments, residues responsible for the binding of Psb31 to PSII intrinsic proteins were suggested. The results are discussed in relation to the copy number of extrinsic proteins in higher plant PSII.

PubMed: 23988112
DOI: 10.1021/bi400770d

Experimental method

X-RAY DIFFRACTION (1.55 Å)