ID   LHB2_CERSP              Reviewed;          51 AA.
AC   P0C0Y2; P02952;
DT   21-JUL-1986, integrated into UniProtKB/Swiss-Prot.
DT   23-JAN-2007, sequence version 2.
DT   03-AUG-2022, entry version 68.
DE   RecName: Full=Light-harvesting protein B-800/850 beta chain;
DE   AltName: Full=Antenna pigment protein beta chain;
DE   AltName: Full=LH-3B;
GN   Name=pucB;
OS   Cereibacter sphaeroides (Rhodobacter sphaeroides).
OC   Bacteria; Proteobacteria; Alphaproteobacteria; Rhodobacterales;
OC   Rhodobacteraceae; Cereibacter.
OX   NCBI_TaxID=1063;
RN   [1]
RP   NUCLEOTIDE SEQUENCE [GENOMIC DNA].
RA   Ashby M.K., Coomber S.A., Hunter C.N.;
RT   "Cloning, nucleotide sequence and transfer of genes for the B800-850 light
RT   harvesting complex of Rhodobacter sphaeroides.";
RL   FEBS Lett. 213:245-248(1987).
RN   [2]
RP   NUCLEOTIDE SEQUENCE [GENOMIC DNA].
RX   PubMed=2693605; DOI=10.1099/00221287-135-7-1809;
RA   Burgess J.G., Ashby M.K., Hunter C.N.;
RT   "Characterization and complementation of a mutant of Rhodobacter
RT   sphaeroides with a chromosomal deletion in the light-harvesting (LH2)
RT   genes.";
RL   J. Gen. Microbiol. 135:1809-1816(1989).
RN   [3]
RP   PROTEIN SEQUENCE OF 2-51.
RC   STRAIN=R-26.1;
RX   PubMed=6384009; DOI=10.1515/bchm2.1984.365.2.703;
RA   Theiler R., Suter F., Wiemken V., Zuber H.;
RT   "The light-harvesting polypeptides of Rhodopseudomonas sphaeroides R-26.1.
RT   I. Isolation, purification and sequence analyses.";
RL   Hoppe-Seyler's Z. Physiol. Chem. 365:703-719(1984).
CC   -!- FUNCTION: Antenna complexes are light-harvesting systems, which
CC       transfer the excitation energy to the reaction centers.
CC   -!- SUBUNIT: The core complex is formed by different alpha and beta chains,
CC       binding bacteriochlorophyll molecules, and arranged most probably in
CC       tetrameric structures disposed around the reaction center. The non-
CC       pigmented gamma chains may constitute additional components.
CC   -!- SUBCELLULAR LOCATION: Cell inner membrane; Single-pass type II membrane
CC       protein.
CC   -!- MISCELLANEOUS: This polypeptide (LH-3B) and LH-2 constitute the B-
CC       800/850 complex of R.sphaeroides 2.4.1 and the spectrally altered B-850
CC       complex isolated from the blue-green mutant R-27.1, which absorbs at
CC       860 nM.
CC   -!- SIMILARITY: Belongs to the antenna complex beta subunit family.
CC       {ECO:0000305}.
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DR   EMBL; X05200; CAA28832.1; -; Genomic_DNA.
DR   EMBL; M28360; AAA26130.1; -; Genomic_DNA.
DR   PIR; A26645; A26645.
DR   PIR; B27087; LBRFBS.
DR   RefSeq; WP_002720479.1; NZ_QXDK01000009.1.
DR   AlphaFoldDB; P0C0Y2; -.
DR   SMR; P0C0Y2; -.
DR   GeneID; 57470633; -.
DR   GeneID; 67447048; -.
DR   OMA; AYIYTPW; -.
DR   OrthoDB; 2043694at2; -.
DR   GO; GO:0016021; C:integral component of membrane; IEA:UniProtKB-KW.
DR   GO; GO:0005886; C:plasma membrane; IEA:UniProtKB-SubCell.
DR   GO; GO:0030077; C:plasma membrane light-harvesting complex; IEA:InterPro.
DR   GO; GO:0042314; F:bacteriochlorophyll binding; IEA:UniProtKB-KW.
DR   GO; GO:0045156; F:electron transporter, transferring electrons within the cyclic electron transport pathway of photosynthesis activity; IEA:InterPro.
DR   GO; GO:0046872; F:metal ion binding; IEA:UniProtKB-KW.
DR   GO; GO:0019684; P:photosynthesis, light reaction; IEA:InterPro.
DR   Gene3D; 1.20.5.250; -; 1.
DR   InterPro; IPR000066; Antenna_a/b.
DR   InterPro; IPR023623; Antenna_beta_CS.
DR   InterPro; IPR023624; Antenna_beta_dom_sf.
DR   InterPro; IPR002362; LHB-1/5.
DR   InterPro; IPR035889; Light-harvesting_complex.
DR   Pfam; PF00556; LHC; 1.
DR   PIRSF; PIRSF002900; Antenna_beta; 1.
DR   PRINTS; PR00674; LIGHTHARVSTB.
DR   SUPFAM; SSF56918; SSF56918; 1.
DR   PROSITE; PS00969; ANTENNA_COMP_BETA; 1.
PE   1: Evidence at protein level;
KW   Antenna complex; Bacteriochlorophyll; Cell inner membrane; Cell membrane;
KW   Chlorophyll; Chromophore; Direct protein sequencing;
KW   Light-harvesting polypeptide; Magnesium; Membrane; Metal-binding;
KW   Transmembrane; Transmembrane helix.
FT   INIT_MET        1
FT                   /note="Removed"
FT                   /evidence="ECO:0000269|PubMed:6384009"
FT   CHAIN           2..51
FT                   /note="Light-harvesting protein B-800/850 beta chain"
FT                   /id="PRO_0000099835"
FT   TOPO_DOM        2..23
FT                   /note="Cytoplasmic"
FT                   /evidence="ECO:0000255"
FT   TRANSMEM        24..46
FT                   /note="Helical"
FT                   /evidence="ECO:0000255"
FT   TOPO_DOM        47..51
FT                   /note="Periplasmic"
FT                   /evidence="ECO:0000255"
FT   BINDING         22
FT                   /ligand="a bacteriochlorophyll"
FT                   /ligand_id="ChEBI:CHEBI:38201"
FT                   /ligand_part="Mg"
FT                   /ligand_part_id="ChEBI:CHEBI:25107"
FT                   /note="axial binding residue"
FT                   /evidence="ECO:0000255"
FT   BINDING         40
FT                   /ligand="a bacteriochlorophyll"
FT                   /ligand_id="ChEBI:CHEBI:38201"
FT                   /ligand_part="Mg"
FT                   /ligand_part_id="ChEBI:CHEBI:25107"
FT                   /note="axial binding residue"
FT                   /evidence="ECO:0000255"
FT   CONFLICT        38
FT                   /note="I -> L (in Ref. 1; CAA28832)"
FT                   /evidence="ECO:0000305"
SQ   SEQUENCE   51 AA;  5448 MW;  103C6A87EF6CDAF2 CRC64;
     MTDDLNKVWP SGLTVAEAEE VHKQLILGTR VFGGMALIAH FLAAAATPWL G