4H44

2.70 A Cytochrome b6f Complex Structure From Nostoc PCC 7120


Experimental Data Snapshot

  • Method: X-RAY DIFFRACTION
  • Resolution: 2.70 Å
  • R-Value Free: 0.246 
  • R-Value Work: 0.220 
  • R-Value Observed: 0.221 

wwPDB Validation   3D Report Full Report


This is version 1.1 of the entry. See complete history


Literature

Quinone-dependent proton transfer pathways in the photosynthetic cytochrome b6f complex

Hasan, S.S.Yamashita, E.Baniulis, D.Cramer, W.A.

(2013) Proc Natl Acad Sci U S A 110: 4297-4302

  • DOI: 10.1073/pnas.1222248110
  • Primary Citation of Related Structures:  
    4H0L, 4H13, 4H44

  • PubMed Abstract: 
  • As much as two-thirds of the proton gradient used for transmembrane free energy storage in oxygenic photosynthesis is generated by the cytochrome b6f complex. The proton uptake pathway from the electrochemically negative (n) aqueous phase to the n-side quinone binding site of the complex, and a probable route for proton exit to the positive phase resulting from quinol oxidation, are defined in a 2 ...

    As much as two-thirds of the proton gradient used for transmembrane free energy storage in oxygenic photosynthesis is generated by the cytochrome b6f complex. The proton uptake pathway from the electrochemically negative (n) aqueous phase to the n-side quinone binding site of the complex, and a probable route for proton exit to the positive phase resulting from quinol oxidation, are defined in a 2.70-Å crystal structure and in structures with quinone analog inhibitors at 3.07 Å (tridecyl-stigmatellin) and 3.25-Å (2-nonyl-4-hydroxyquinoline N-oxide) resolution. The simplest n-side proton pathway extends from the aqueous phase via Asp20 and Arg207 (cytochrome b6 subunit) to quinone bound axially to heme c(n). On the positive side, the heme-proximal Glu78 (subunit IV), which accepts protons from plastosemiquinone, defines a route for H(+) transfer to the aqueous phase. These pathways provide a structure-based description of the quinone-mediated proton transfer responsible for generation of the transmembrane electrochemical potential gradient in oxygenic photosynthesis.


    Organizational Affiliation

    Department of Biological Sciences, Purdue University, West Lafayette, IN 47907, USA.



Macromolecules
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Entity ID: 1
MoleculeChainsSequence LengthOrganismDetailsImage
Cytochrome b6A215Nostoc sp. PCC 7120 = FACHB-418Mutation(s): 0 
Gene Names: petBalr3421
Membrane Entity: Yes 
UniProt
Find proteins for P0A384 (Nostoc sp. (strain PCC 7120 / SAG 25.82 / UTEX 2576))
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Go to UniProtKB:  P0A384
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  • Reference Sequence
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Entity ID: 2
MoleculeChainsSequence LengthOrganismDetailsImage
Cytochrome b6-f complex subunit 4B160Nostoc sp. PCC 7120 = FACHB-418Mutation(s): 0 
Gene Names: petDalr3422
Membrane Entity: Yes 
UniProt
Find proteins for Q93SX1 (Nostoc sp. (strain PCC 7120 / SAG 25.82 / UTEX 2576))
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  • Reference Sequence
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Entity ID: 3
MoleculeChainsSequence LengthOrganismDetailsImage
Apocytochrome fC289Nostoc sp. PCC 7120 = FACHB-418Mutation(s): 0 
Gene Names: petAall2452
Membrane Entity: Yes 
UniProt
Find proteins for Q93SW9 (Nostoc sp. (strain PCC 7120 / SAG 25.82 / UTEX 2576))
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Entity ID: 4
MoleculeChainsSequence LengthOrganismDetailsImage
Cytochrome b6-f complex iron-sulfur subunit 1D179Nostoc sp. PCC 7120 = FACHB-418Mutation(s): 0 
Gene Names: petC1all2453
EC: 1.10.9.1 (PDB Primary Data), 7.1.1.6 (UniProt)
Membrane Entity: Yes 
UniProt
Find proteins for Q93SX0 (Nostoc sp. (strain PCC 7120 / SAG 25.82 / UTEX 2576))
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Entity ID: 5
MoleculeChainsSequence LengthOrganismDetailsImage
Cytochrome b6-f complex subunit 6E31Nostoc sp. PCC 7120 = FACHB-418Mutation(s): 0 
Gene Names: petLasl1922
Membrane Entity: Yes 
UniProt
Find proteins for Q8YVQ2 (Nostoc sp. (strain PCC 7120 / SAG 25.82 / UTEX 2576))
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Entity ID: 6
MoleculeChainsSequence LengthOrganismDetailsImage
Cytochrome b6-f complex subunit 7F34Nostoc sp. PCC 7120 = FACHB-418Mutation(s): 0 
Gene Names: petMasl4754
Membrane Entity: Yes 
UniProt
Find proteins for P0A3Y1 (Nostoc sp. (strain PCC 7120 / SAG 25.82 / UTEX 2576))
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Entity ID: 7
MoleculeChainsSequence LengthOrganismDetailsImage
Cytochrome b6-f complex subunit 5G37Nostoc sp. PCC 7120 = FACHB-418Mutation(s): 0 
Gene Names: petGasr1366
Membrane Entity: Yes 
UniProt
Find proteins for P58246 (Nostoc sp. (strain PCC 7120 / SAG 25.82 / UTEX 2576))
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Entity ID: 8
MoleculeChainsSequence LengthOrganismDetailsImage
Cytochrome b6-f complex subunit 8H29Nostoc sp. PCC 7120 = FACHB-418Mutation(s): 0 
Gene Names: petNasl4263
Membrane Entity: Yes 
UniProt
Find proteins for P61048 (Nostoc sp. (strain PCC 7120 / SAG 25.82 / UTEX 2576))
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Go to UniProtKB:  P61048
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  • Reference Sequence
Small Molecules
Ligands 12 Unique
IDChainsName / Formula / InChI Key2D Diagram3D Interactions
CLA
Query on CLA

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R [auth B]CHLOROPHYLL A
C55 H72 Mg N4 O5
VIQFHHZSLDFWDU-AENOIHSZSA-M
 Ligand Interaction
OPC
Query on OPC

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S [auth B], U [auth C](7R,17E)-4-HYDROXY-N,N,N,7-TETRAMETHYL-7-[(8E)-OCTADEC-8-ENOYLOXY]-10-OXO-3,5,9-TRIOXA-4-PHOSPHAHEPTACOS-17-EN-1-AMINIUM 4-OXIDE
C45 H87 N O8 P
CTQFGTDUPDRLRZ-CNMUNUSJSA-O
 Ligand Interaction
SQD
Query on SQD

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X [auth D]1,2-DI-O-ACYL-3-O-[6-DEOXY-6-SULFO-ALPHA-D-GLUCOPYRANOSYL]-SN-GLYCEROL
C41 H78 O12 S
RVUUQPKXGDTQPG-JUDHQOGESA-N
 Ligand Interaction
HEM
Query on HEM

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I [auth A], J [auth A], K [auth A], T [auth C]PROTOPORPHYRIN IX CONTAINING FE
C34 H32 Fe N4 O4
KABFMIBPWCXCRK-RGGAHWMASA-L
 Ligand Interaction
7PH
Query on 7PH

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V [auth C](1R)-2-(dodecanoyloxy)-1-[(phosphonooxy)methyl]ethyl tetradecanoate
C29 H57 O8 P
UYOIGTVMJVHOSC-HHHXNRCGSA-N
 Ligand Interaction
BCR
Query on BCR

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BA [auth G]BETA-CAROTENE
C40 H56
OENHQHLEOONYIE-JLTXGRSLSA-N
 Ligand Interaction
UMQ
Query on UMQ

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L [auth A], M [auth A], O [auth A], Q [auth A], Z [auth F]UNDECYL-MALTOSIDE
C23 H44 O11
UYEMNFYVTFDKRG-ZNGNCRBCSA-N
 Ligand Interaction
8K6
Query on 8K6

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P [auth A]Octadecane
C18 H38
RZJRJXONCZWCBN-UHFFFAOYSA-N
 Ligand Interaction
MYS
Query on MYS

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N [auth A]PENTADECANE
C15 H32
YCOZIPAWZNQLMR-UHFFFAOYSA-N
 Ligand Interaction
FES
Query on FES

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Y [auth D]FE2/S2 (INORGANIC) CLUSTER
Fe2 S2
NIXDOXVAJZFRNF-UHFFFAOYSA-N
 Ligand Interaction
OCT
Query on OCT

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AA [auth F]N-OCTANE
C8 H18
TVMXDCGIABBOFY-UHFFFAOYSA-N
 Ligand Interaction
CD
Query on CD

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W [auth C]CADMIUM ION
Cd
WLZRMCYVCSSEQC-UHFFFAOYSA-N
 Ligand Interaction
Experimental Data & Validation

Experimental Data

  • Method: X-RAY DIFFRACTION
  • Resolution: 2.70 Å
  • R-Value Free: 0.246 
  • R-Value Work: 0.220 
  • R-Value Observed: 0.221 
  • Space Group: P 61 2 2
Unit Cell:
Length ( Å )Angle ( ˚ )
a = 159.127α = 90
b = 159.127β = 90
c = 364.373γ = 120
Software Package:
Software NamePurpose
ADSCdata collection
REFMACrefinement
HKL-2000data reduction
HKL-2000data scaling
REFMACphasing
PHENIXrefinement

Structure Validation

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Entry History 

Deposition Data

Revision History  (Full details and data files)

  • Version 1.0: 2013-02-20
    Type: Initial release
  • Version 1.1: 2013-04-03
    Changes: Database references