PDBsum entry 6yac

Photosynthesis

PDB id: 6yac

Contents

Protein chains

743 a.a.

733 a.a.

80 a.a.

143 a.a.

66 a.a.

154 a.a.

97 a.a.

88 a.a.

31 a.a.

42 a.a.

81 a.a.

157 a.a.

193 a.a.

208 a.a.

221 a.a.

198 a.a.

97 a.a.

Ligands

CL0

CLA ×141

PQN ×2

SF4 ×3

BCR ×27

LHG ×8

LMT ×6

LMG ×19

DGD ×8

LUT ×7

CHL

XAT ×2

C7Z

FES

Metals

_CA

Waters ×56

References listed in PDB file

Key reference

• Title: The structure of a triple complex of plant photosystem i with ferredoxin and plastocyanin.
• Authors: I.Caspy, A.Borovikova-Sheinker, D.Klaiman, Y.Shkolnisky, N.Nelson.
• Ref.: Nat Plants, 2020, 6, 1300-1305. [DOI no: 10.1038/s41477-020-00779-9]
• PubMed id: 33020607

Abstract

The ability of photosynthetic organisms to use sunlight as a sole source of energy is endowed by two large membrane complexes-photosystem I (PSI) and photosystem II (PSII). PSI and PSII are the fundamental components of oxygenic photosynthesis, providing oxygen, food and an energy source for most living organisms on Earth. Currently, high-resolution crystal structures of these complexes from various organisms are available. The crystal structures of megadalton complexes have revealed excitation transfer and electron-transport pathways within the various complexes. PSI is defined as plastocyanin-ferredoxin oxidoreductase but a high-resolution structure of the entire triple supercomplex is not available. Here, using a new cryo-electron microscopy technique, we solve the structure of native plant PSI in complex with its electron donor plastocyanin and the electron acceptor ferredoxin. We reveal all of the contact sites and the modes of interaction between the interacting electron carriers and PSI.