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6zoo

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Photosystem I reduced Plastocyanin Complex

Structural highlights

6zoo is a 10 chain structure with sequence from Pisum sativum. Full crystallographic information is available from OCA. For a guided tour on the structure components use FirstGlance.
Method:	Electron Microscopy, Resolution 2.74Å
Ligands:	, , , , , , , , , , , ,
Resources:	FirstGlance, OCA, PDBe, RCSB, PDBsum, ProSAT

Function

CAB6_ARATH The light-harvesting complex (LHC) functions as a light receptor, it captures and delivers excitation energy to photosystems with which it is closely associated.

Publication Abstract from PubMed

Photosystem I is defined as plastocyanin-ferredoxin oxidoreductase. Taking advantage of genetic engineering, kinetic analyses and cryo-EM, our data provide novel mechanistic insights into binding and electron transfer between PSI and Pc. Structural data at 2.74 A resolution reveals strong hydrophobic interactions in the plant PSI-Pc ternary complex, leading to exclusion of water molecules from PsaA-PsaB/Pc interface once the PSI-Pc complex forms. Upon oxidation of Pc, a slight tilt of bound oxidized Pc allows water molecules to accommodate the space between Pc and PSI to drive Pc dissociation. Such a scenario is consistent with the six times larger dissociation constant of oxidized as compared with reduced Pc and mechanistically explains how this molecular machine optimized electron transfer for fast turnover.

Structure of plant photosystem I-plastocyanin complex reveals strong hydrophobic interactions.,Caspy I, Fadeeva M, Kuhlgert S, Borovikova-Sheinker A, Klaiman D, Masrati G, Drepper F, Ben-Tal N, Hippler M, Nelson N Biochem J. 2021 Jun 25;478(12):2371-2384. doi: 10.1042/BCJ20210267. PMID:34085703^[1]

From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine.

References

↑ Caspy I, Fadeeva M, Kuhlgert S, Borovikova-Sheinker A, Klaiman D, Masrati G, Drepper F, Ben-Tal N, Hippler M, Nelson N. Structure of plant photosystem I-plastocyanin complex reveals strong hydrophobic interactions. Biochem J. 2021 Jun 25;478(12):2371-2384. PMID:34085703 doi:10.1042/BCJ20210267