9LTI | pdb_00009lti

Cryo-EM structure of LH1-RC from Ery. sanguineus


Experimental Data Snapshot

  • Method: ELECTRON MICROSCOPY
  • Resolution: 2.27 Å
  • Aggregation State: PARTICLE 
  • Reconstruction Method: SINGLE PARTICLE 

wwPDB Validation 3D Report Full Report

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Literature

Cryo-EM structures of photocomplexes from the free-living aerobic anoxygenic phototrophic bacterium Erythrobacter sanguineus.

Yue, X.Y.Wang, G.L.Zou, M.J.Ma, F.Wang-Otomo, Z.Y.Madigan, M.T.Yu, L.J.

(2026) Structure 34: 334

  • DOI: https://doi.org/10.1016/j.str.2025.10.017
  • Primary Citation Related Structures: 
    9LT4, 9LTI

  • PubMed Abstract: 

    Aerobic anoxygenic phototrophic bacteria (AAPB) are widely distributed in nature and they are important members of the marine phototrophic community. However, a structural and functional understanding of the AAPB photosynthetic apparatus is still lacking. Here, we present cryo-EM structures of the LH1-RC (core) and LH2 (peripheral) photocomplexes from the model aerobic phototroph Erythrobacter (Ery.) sanguineus. The LH1 αβ-heterodimers bind the carotenoids bacteriorubixanthinal and caloxanthin-pigments that are absent from anaerobic anoxygenic phototrophs-to form a closed ring structure. Ery. sanguineus LH1-RC contains a lipid-anchored polypeptide unrelated to any of the auxiliary proteins identified in the core complexes of purple bacteria so far. The Ery. sanguineus LH2 complex shows unique absorption characteristics, with its Q y transition being blue-shifted to 814 nm. This work provides structural insights into the unusual photosynthetic properties of AAPB and points to new avenues to further explore their biology.


  • Organizational Affiliation
    • Photosynthesis Research Center, State Key Laboratory of Forage Breeding-by-Design and Utilization, Institute of Botany, Chinese Academy of Sciences, Beijing 100093, China; University of Chinese Academy of Sciences, Beijing 100049, China.

Macromolecule Content 

  • Total Structure Weight: 385.53 kDa 
  • Atom Count: 22,831 
  • Modeled Residue Count: 2,222 
  • Deposited Residue Count: 2,856 
  • Unique protein chains: 6

Macromolecules

Find similar proteins by:|  3D Structure
Entity ID: 1
MoleculeChains  Sequence LengthOrganismDetailsImage
Light-harvesting complex 1 alpha chain64Erythrobacter sanguineusMutation(s): 0 
UniProt
Find proteins for A0A1M7RZ65 (Erythrobacter sanguineus)
Explore A0A1M7RZ65 
Go to UniProtKB:  A0A1M7RZ65
Entity Groups
Sequence Clusters30% Identity50% Identity70% Identity90% Identity95% Identity100% Identity
UniProt GroupA0A1M7RZ65
Sequence Annotations
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Reference Sequence
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Entity ID: 2
MoleculeChains  Sequence LengthOrganismDetailsImage
Antenna complex alpha/beta subunit52Erythrobacter sanguineusMutation(s): 0 
UniProt
Find proteins for A0A1M7RZ98 (Erythrobacter sanguineus)
Explore A0A1M7RZ98 
Go to UniProtKB:  A0A1M7RZ98
Entity Groups
Sequence Clusters30% Identity50% Identity70% Identity90% Identity95% Identity100% Identity
UniProt GroupA0A1M7RZ98
Sequence Annotations
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Reference Sequence
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Entity ID: 3
MoleculeChains  Sequence LengthOrganismDetailsImage
Reaction center protein L chainGA [auth L]274Erythrobacter sanguineusMutation(s): 0 
UniProt
Find proteins for A0A1M7RZC0 (Erythrobacter sanguineus)
Explore A0A1M7RZC0 
Go to UniProtKB:  A0A1M7RZC0
Entity Groups
Sequence Clusters30% Identity50% Identity70% Identity90% Identity95% Identity100% Identity
UniProt GroupA0A1M7RZC0
Sequence Annotations
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Reference Sequence
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Entity ID: 4
MoleculeChains  Sequence LengthOrganismDetailsImage
Photosynthetic reaction center H subunitHA [auth H]268Erythrobacter sanguineusMutation(s): 0 
UniProt
Find proteins for A0A1M7RZD6 (Erythrobacter sanguineus)
Explore A0A1M7RZD6 
Go to UniProtKB:  A0A1M7RZD6
Entity Groups
Sequence Clusters30% Identity50% Identity70% Identity90% Identity95% Identity100% Identity
UniProt GroupA0A1M7RZD6
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Reference Sequence
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Entity ID: 5
MoleculeChains  Sequence LengthOrganismDetailsImage
Reaction center protein M chainIA [auth M]323Erythrobacter sanguineusMutation(s): 0 
UniProt
Find proteins for A0A1M7RZG6 (Erythrobacter sanguineus)
Explore A0A1M7RZG6 
Go to UniProtKB:  A0A1M7RZG6
Entity Groups
Sequence Clusters30% Identity50% Identity70% Identity90% Identity95% Identity100% Identity
UniProt GroupA0A1M7RZG6
Sequence Annotations
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Reference Sequence
Find similar proteins by:|  3D Structure
Entity ID: 6
MoleculeChains  Sequence LengthOrganismDetailsImage
Secreted proteinJA [auth T]135Erythrobacter sanguineusMutation(s): 0 
UniProt
Find proteins for A0A1M7SD26 (Erythrobacter sanguineus)
Explore A0A1M7SD26 
Go to UniProtKB:  A0A1M7SD26
Entity Groups
Sequence Clusters30% Identity50% Identity70% Identity90% Identity95% Identity100% Identity
UniProt GroupA0A1M7SD26
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Reference Sequence

Small Molecules

Ligands 13 Unique
IDChains Name / Formula / InChI Key2D Diagram3D Interactions
BCL
(Subject of Investigation/LOI)

Query on BCL



Download:Ideal Coordinates CCD File
CB [auth G]
CC [auth P]
CD [auth g]
ED [auth q]
FC [auth b]
CB [auth G],
CC [auth P],
CD [auth g],
ED [auth q],
FC [auth b],
FD [auth i],
GB [auth Q],
GC [auth a],
GD [auth L],
HC [auth p],
HD [auth L],
JC [auth o],
KA [auth A],
KB [auth I],
KC [auth n],
LC [auth s],
MB [auth J],
NA [auth B],
PB [auth K],
PC [auth r],
QA [auth C],
QC [auth k],
RB [auth R],
SC [auth j],
TC [auth c],
UA [auth D],
UB [auth S],
UD [auth M],
VC [auth d],
WB [auth N],
WD [auth M],
XA [auth E],
XC [auth e],
ZA [auth F],
ZB [auth O],
ZC [auth f]
BACTERIOCHLOROPHYLL A
C55 H74 Mg N4 O6
DSJXIQQMORJERS-AGGZHOMASA-M
BPH
(Subject of Investigation/LOI)

Query on BPH



Download:Ideal Coordinates CCD File
ID [auth L],
KD [auth L]
BACTERIOPHEOPHYTIN A
C55 H76 N4 O6
KWOZSBGNAHVCKG-SZQBJALDSA-N
PGV
(Subject of Investigation/LOI)

Query on PGV



Download:Ideal Coordinates CCD File
BB [auth F]
BE [auth M]
DE [auth T]
EB [auth G]
FE [auth T]
BB [auth F],
BE [auth M],
DE [auth T],
EB [auth G],
FE [auth T],
MD [auth L],
ND [auth L],
WA [auth D]
(1R)-2-{[{[(2S)-2,3-DIHYDROXYPROPYL]OXY}(HYDROXY)PHOSPHORYL]OXY}-1-[(PALMITOYLOXY)METHYL]ETHYL (11E)-OCTADEC-11-ENOATE
C40 H77 O10 P
ADYWCMPUNIVOEA-GPJPVTGXSA-N
UQ8
(Subject of Investigation/LOI)

Query on UQ8



Download:Ideal Coordinates CCD File
JD [auth L],
LD [auth L],
VD [auth M]
Ubiquinone-8
C49 H74 O4
ICFIZJQGJAJRSU-SGHXUWJISA-N
LHG
(Subject of Investigation/LOI)

Query on LHG



Download:Ideal Coordinates CCD File
EE [auth T]1,2-DIPALMITOYL-PHOSPHATIDYL-GLYCEROLE
C38 H75 O10 P
BIABMEZBCHDPBV-MPQUPPDSSA-N
PEF

Query on PEF



Download:Ideal Coordinates CCD File
AE [auth M]DI-PALMITOYL-3-SN-PHOSPHATIDYLETHANOLAMINE
C37 H74 N O8 P
SLKDGVPOSSLUAI-PGUFJCEWSA-N
H4X
(Subject of Investigation/LOI)

Query on H4X



Download:Ideal Coordinates CCD File
YD [auth M](6~{E},8~{E},10~{E},12~{E},14~{E},16~{E},18~{E},20~{E},22~{E},24~{E},26~{E})-2,31-dimethoxy-2,6,10,14,19,23,27,31-octamethyl-dotriaconta-6,8,10,12,14,16,18,20,22,24,26-undecaene
C42 H64 O2
LCTIOHZQWXQPIB-VYCPWLLESA-N
A1ELD
(Subject of Investigation/LOI)

Query on A1ELD



Download:Ideal Coordinates CCD File
AC [auth O]
BD [auth g]
DD [auth q]
EC [auth b]
IC [auth o]
AC [auth O],
BD [auth g],
DD [auth q],
EC [auth b],
IC [auth o],
MA [auth A],
MC [auth r],
OB [auth J],
PA [auth B],
RA [auth C],
RC [auth j],
SB [auth R],
TB [auth R],
UC [auth d],
WC [auth e],
YC [auth f]
(2~{Z},4~{E},6~{E},8~{E},10~{E},12~{E},14~{E},16~{E})-2-[(1~{Z},3~{Z},5~{E})-8-methoxy-4,8-dimethyl-nona-1,3,5-trienyl]-6,11,15-trimethyl-17-[(4~{R})-2,6,6-trimethyl-4-oxidanyl-cyclohexen-1-yl]heptadeca-2,4,6,8,10,12,14,16-octaenal
C41 H56 O3
DFOYVSCLGRVGJK-PCDZQMFBSA-N
A1EL2
(Subject of Investigation/LOI)

Query on A1EL2



Download:Ideal Coordinates CCD File
AB [auth F]
BC [auth O]
DB [auth G]
DC [auth P]
HB [auth Q]
AB [auth F],
BC [auth O],
DB [auth G],
DC [auth P],
HB [auth Q],
LA [auth A],
LB [auth I],
NB [auth J],
NC [auth r],
OA [auth B],
OC [auth r],
QB [auth K],
SA [auth C],
VA [auth D],
XB [auth N],
YA [auth E]
(1~{R},2~{R})-3,3,5-trimethyl-4-[(1~{E},3~{E},5~{E},7~{E},9~{E},11~{E},13~{E},15~{E},17~{E})-3,7,12,16-tetramethyl-18-[(4~{R})-2,6,6-trimethyl-4-oxidanyl-cyclohexen-1-yl]octadeca-1,3,5,7,9,11,13,15,17-nonaenyl]cyclohex-4-ene-1,2-diol
C40 H56 O3
PKHJWTKRKQNNJE-RJLXQHJHSA-N
LMT

Query on LMT



Download:Ideal Coordinates CCD File
FB [auth G],
OD [auth L],
YB [auth N]
DODECYL-BETA-D-MALTOSIDE
C24 H46 O11
NLEBIOOXCVAHBD-QKMCSOCLSA-N
8K6

Query on 8K6



Download:Ideal Coordinates CCD File
AD [auth f]
IB [auth Q]
JB [auth Q]
PD [auth L]
QD [auth L]
AD [auth f],
IB [auth Q],
JB [auth Q],
PD [auth L],
QD [auth L],
RD [auth L],
SD [auth L],
TA [auth C],
TD [auth H],
VB [auth S],
ZD [auth M]
Octadecane
C18 H38
RZJRJXONCZWCBN-UHFFFAOYSA-N
PO4

Query on PO4



Download:Ideal Coordinates CCD File
CE [auth M]PHOSPHATE ION
O4 P
NBIIXXVUZAFLBC-UHFFFAOYSA-K
FE
(Subject of Investigation/LOI)

Query on FE



Download:Ideal Coordinates CCD File
XD [auth M]FE (III) ION
Fe
VTLYFUHAOXGGBS-UHFFFAOYSA-N

Experimental Data & Validation

Experimental Data

  • Method: ELECTRON MICROSCOPY
  • Resolution: 2.27 Å
  • Aggregation State: PARTICLE 
  • Reconstruction Method: SINGLE PARTICLE 
EM Software:
TaskSoftware PackageVersion
MODEL REFINEMENTPHENIX1.19.2_4158

Structure Validation

View Full Validation Report



Entry History 

& Funding Information

Deposition Data


Funding OrganizationLocationGrant Number
Ministry of Science and Technology (MoST, China)China2022YFC3401800
Ministry of Science and Technology (MoST, China)ChinaZR2019ZD48
Ministry of Science and Technology (MoST, China)China2022SZX12

Revision History  (Full details and data files)

  • Version 1.0: 2025-12-10
    Type: Initial release
  • Version 1.1: 2026-02-25
    Changes: Data collection, Database references