2WSC: Improved Model of Plant Photosystem I

Citation:
Abstract
Photosystem I functions as a sunlight energy converter, catalyzing one of the initial steps in driving oxygenic photosynthesis in cyanobacteria, algae, and higher plants. Functionally, Photosystem I captures sunlight and transfers the excitation energy through an intricate and precisely organized antenna system, consisting of a pigment network, to the center of the molecule, where it is used in the transmembrane electron transfer reaction. Our current understanding of the sophisticated mechanisms underlying these processes has profited greatly from elucidation of the crystal structures of the Photosystem I complex. In this report, we describe the developments that ultimately led to enhanced structural information of plant Photosystem I. In addition, we report an improved crystallographic model at 3.3-A resolution, which allows analysis of the structure in more detail. An improved electron density map yielded identification and tracing of subunit PsaK. The location of an additional ten beta-carotenes as well as five chlorophylls and several loop regions, which were previously uninterpretable, are now modeled. This represents the most complete plant Photosystem I structure obtained thus far, revealing the locations of and interactions among 17 protein subunits and 193 non-covalently bound photochemical cofactors. Using the new crystal structure, we examine the network of contacts among the protein subunits from the structural perspective, which provide the basis for elucidating the functional organization of the complex.
PDB ID: 2WSCDownload
MMDB ID: 163672
PDB Deposition Date: 2009/9/4
Updated in MMDB: 2018/06
Experimental Method:
x-ray diffraction
Resolution: 3.3  Å
Source Organism:
Hordeum vulgare
Similar Structures:
Biological Unit for 2WSC: octadecameric; determined by author and by software (PISA)
Molecular Components in 2WSC
Label Count Molecule
Proteins (18 molecules)
1
At3g54890
Molecule annotation
1
Type II Chlorophyll A/B Binding Protein From Photosystem I
Molecule annotation
1
Lhca3
Molecule annotation
1
Chlorophyll A-B Binding Protein P4, Chloroplastic
Molecule annotation
1
Photosystem I P700 Chlorophyll a Apoprotein A1(Gene symbol: psaA)
Molecule annotation
1
Photosystem I P700 Chlorophyll a Apoprotein A2(Gene symbol: psaB)
Molecule annotation
1
Photosystem I Iron-sulfur Center(Gene symbol: psaC)
Molecule annotation
1
Photosystem I Reaction Center Subunit II, Chloroplastic(Gene symbol: LOC110778649)
Molecule annotation
1
Photosystem I Reaction Center Subunit IV A, Chloroplastic(Gene symbol: PSAE-1)
Molecule annotation
1
Photosystem I Reaction Center Subunit Iii, Chloroplastic(Gene symbol: LOC110775268)
Molecule annotation
1
Photosystem I Reaction Center Subunit V, Chloroplastic(Gene symbol: LOC110775996)
Molecule annotation
1
Photosystem I Reaction Center Subunit VI, Chloroplastic(Gene symbol: LOC110801787)
Molecule annotation
1
Photosystem I Reaction Center Subunit Viii(Gene symbol: psaI)
Molecule annotation
1
Photosystem I Reaction Center Subunit IX(Gene symbol: psaJ)
Molecule annotation
1
Photosystem I Reaction Center Subunit Psak, Chloroplastic
Molecule annotation
1
Photosystem I Reaction Center Subunit XI, Chloroplastic(Gene symbol: LOC110791435)
Molecule annotation
1
Photosystem I-N Subunit
Molecule annotation
1
Photosystem I-N Subunit
Molecule annotation
Chemicals (256 molecules)
1
173
2
45
3
13
4
18
5
2
6
1
7
3
8
1
* Click molecule labels to explore molecular sequence information.

Citing MMDB
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