2PPS

PHOTOSYNTHETIC REACTION CENTER AND CORE ANTENNA SYSTEM (TRIMERIC), ALPHA CARBON ONLY

• PDB DOI: https://doi.org/10.2210/pdb2PPS/pdb
• Entry: 2PPS supersedes: 1PPS

• Classification: PHOTOSYNTHESIS
• Organism(s): Synechococcus elongatus
• Mutation(s): No 


• Deposited: 1997-05-27 Released: 1998-05-27 
• Deposition Author(s): Krauss, N., Schubert, W.-D., Klukas, O., Fromme, P., Witt, H.T., Saenger, W.

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Experimental Data Snapshot

• Method: X-RAY DIFFRACTION
• Resolution: 4.00 Å

Literature

Photosystem I at 4 A resolution represents the first structural model of a joint photosynthetic reaction centre and core antenna system.

Krauss, N., Schubert, W.D., Klukas, O., Fromme, P., Witt, H.T., Saenger, W.

(1996) Nat Struct Biol 3: 965-973

• PubMed: 8901876 
• DOI: https://doi.org/10.1038/nsb1196-965
• Primary Citation of Related Structures:  
  2PPS


• PubMed Abstract: 
  

  The 4 A X-ray structure model of trimeric photosystem I of the cyanobacterium Synechococcus elongatus reveals 31 transmembrane, nine surface and three stromal alpha-helices per monomer, assigned to the 11 protein subunits: PsaA and PsaB are related by a pseudo two-fold axis normal to the membrane plane, along which the electron transfer pigments are arranged. 65 antenna chlorophyll a (Chl a) molecules separated by < or = 16 A form an oval, clustered net continuous with the electron transfer chain through the second and third Chl a pairs of the electron transfer system. This suggests a dual role for these Chl a both in excitation energy and electron transfer. The architecture of the protein core indicates quinone and iron-sulphur type reaction centres to have a common ancestor.

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Organizational Affiliation: 

Institut für Kristallographie, Freie Universität Berlin, Germany.

Biological Assembly 1  

Global Symmetry: Asymmetric - C1 
Global Stoichiometry: Hetero 6-mer - A2B2C2 Pseudo Symmetry: Asymmetric - C1 
Pseudo Stoichiometry: Hetero 6-mer - A1B1C1D1E1F1 

Biological assembly 1 assigned by authors.

Macromolecule Content

• Total Structure Weight: 197.39 kDa 
• Atom Count: 3,616 
• Modelled Residue Count: 1,366 
• Deposited Residue Count: 1,366 
• Unique protein chains: 6

Macromolecules

Entity ID: 1
Molecule	Chains	Sequence Length	Organism	Details	Image
PHOTOSYSTEM I	A	478	Synechococcus elongatus	Mutation(s): 0

Entity ID: 2
Molecule	Chains	Sequence Length	Organism	Details	Image
PHOTOSYSTEM I	B	503	Synechococcus elongatus	Mutation(s): 0

Entity ID: 3
Molecule	Chains	Sequence Length	Organism	Details	Image
PHOTOSYSTEM I	C [auth L]	111	Synechococcus elongatus	Mutation(s): 0

Entity ID: 4
Molecule	Chains	Sequence Length	Organism	Details	Image
PHOTOSYSTEM I	D [auth K]	64	Synechococcus elongatus	Mutation(s): 0

Entity ID: 5
Molecule	Chains	Sequence Length	Organism	Details	Image
PHOTOSYSTEM I	E [auth F]	130	Synechococcus elongatus	Mutation(s): 0

Entity ID: 6
Molecule	Chains	Sequence Length	Organism	Details	Image
PHOTOSYSTEM I	F [auth C]	80	Synechococcus elongatus	Mutation(s): 0

Small Molecules

Ligands 3 Unique
ID	Chains	Name / Formula / InChI Key	2D Diagram
CLA	AA [auth A], AB [auth B], AC [auth B], BA [auth A], BB [auth B], BC [auth B], CA [auth A], CB [auth B], CC [auth B], DA [auth A], DB [auth B], DC [auth B], EA [auth A], EB [auth B], EC [auth L], FA [auth A], FB [auth B], FC [auth L], G [auth A], GA [auth A], GB [auth B], GC [auth L], H [auth A], HA [auth A], HB [auth B], HC [auth L], I [auth A], IA [auth A], IB [auth B], IC [auth K], J [auth A], JA [auth A], JB [auth B], JC [auth K], K [auth A], KA [auth A], KB [auth B], KC [auth F], L [auth A], LA [auth A], LB [auth B], LC [auth F], M [auth A], MA [auth A], MB [auth B], MC [auth F], N [auth A], NA [auth A], NB [auth B], NC [auth F], O [auth A], OA [auth A], OB [auth B], OC [auth F], P [auth A], PA [auth A], PB [auth B], PC [auth F], Q [auth A], QA [auth A], QB [auth B], QC [auth F], R [auth A], RA [auth A], RB [auth B], RC [auth F], S [auth A], SA [auth A], SB [auth B], SC [auth F], T [auth A], TA [auth A], TB [auth B], U [auth A], UA [auth B], UB [auth B], V [auth A], VA [auth B], VB [auth B], W [auth A], WA [auth B], WB [auth B], X [auth A], XA [auth B], XB [auth B], Y [auth A], YB [auth B], Z [auth A], ZB [auth B]	CHLOROPHYLL A C55 H72 Mg N4 O5 ATNHDLDRLWWWCB-AENOIHSZSA-M
PQN	YA [auth B]	PHYLLOQUINONE C31 H46 O2 MBWXNTAXLNYFJB-NKFFZRIASA-N
SF4	TC [auth C], UC [auth C], ZA [auth B]	IRON/SULFUR CLUSTER Fe4 S4 LJBDFODJNLIPKO-UHFFFAOYSA-N

Experimental Data & Validation

Experimental Data

• Method: X-RAY DIFFRACTION
• Resolution: 4.00 Å
• Space Group: P 6₃

Unit Cell:

Length ( Å )	Angle ( ˚ )
a = 286	α = 90
b = 286	β = 90
c = 167	γ = 120

Software Package:

Software Name	Purpose
MLPHARE	phasing
MOSFLM	data reduction
CCP4	data scaling
ROTAVATA	data scaling

Structure Validation

Entry History 

Deposition Data

• Released Date: 1998-05-27 
Deposition Author(s): Krauss, N., Schubert, W.-D., Klukas, O., Fromme, P., Witt, H.T., Saenger, W.
• This entry supersedes: 1PPS

Revision History  

• Version 1.0: 1998-05-27
  Type: Initial release
  
• Version 1.1: 2008-03-25
  Changes: Version format compliance
• Version 1.2: 2011-07-13
  Changes: Version format compliance
• Version 2.0: 2024-02-21
  Changes: Data collection, Database references, Derived calculations, Non-polymer description, Refinement description