ID   LHA2_HALHR              Reviewed;          65 AA.
AC   P80103;
DT   01-FEB-1994, integrated into UniProtKB/Swiss-Prot.
DT   01-FEB-1994, sequence version 1.
DT   03-AUG-2022, entry version 76.
DE   RecName: Full=Light-harvesting protein B800/830/1020 alpha-2 chain;
DE   AltName: Full=Antenna pigment protein alpha-2 chain;
DE   AltName: Full=EHS-alpha-2;
OS   Halorhodospira halochloris (Ectothiorhodospira halochloris).
OC   Bacteria; Proteobacteria; Gammaproteobacteria; Chromatiales;
OC   Ectothiorhodospiraceae; Halorhodospira.
OX   NCBI_TaxID=1052;
RN   [1]
RP   PROTEIN SEQUENCE.
RC   STRAIN=ATCC 35916 / DSM 1059 / BN 9850 / A;
RX   PubMed=1577009; DOI=10.1111/j.1432-1033.1992.tb16858.x;
RA   Wagner-Huber R., Brunisholz R.A., Bissig I., Frank G., Suter F., Zuber H.;
RT   "The primary structure of the antenna polypeptides of Ectothiorhodospira
RT   halochloris and Ectothiorhodospira halophila. Four core-type antenna
RT   polypeptides in E. halochloris and E. halophila.";
RL   Eur. J. Biochem. 205:917-925(1992).
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   -!- SIMILARITY: Belongs to the antenna complex alpha subunit family.
CC       {ECO:0000305}.
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DR   PIR; S23164; S23164.
DR   AlphaFoldDB; P80103; -.
DR   SMR; P80103; -.
DR   GO; GO:0016021; C:integral component of membrane; IEA:UniProtKB-KW.
DR   GO; GO:0019866; C:organelle inner membrane; IEA:InterPro.
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; 4.10.220.20; -; 1.
DR   InterPro; IPR000066; Antenna_a/b.
DR   InterPro; IPR002361; Antenna_alpha_CS.
DR   InterPro; IPR035889; Light-harvesting_complex.
DR   Pfam; PF00556; LHC; 1.
DR   SUPFAM; SSF56918; SSF56918; 1.
DR   PROSITE; PS00968; ANTENNA_COMP_ALPHA; 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   CHAIN           1..65
FT                   /note="Light-harvesting protein B800/830/1020 alpha-2
FT                   chain"
FT                   /id="PRO_0000099782"
FT   TOPO_DOM        1..13
FT                   /note="Cytoplasmic"
FT                   /evidence="ECO:0000255"
FT   TRANSMEM        14..34
FT                   /note="Helical"
FT                   /evidence="ECO:0000255"
FT   TOPO_DOM        35..65
FT                   /note="Periplasmic"
FT                   /evidence="ECO:0000255"
FT   BINDING         29
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"
SQ   SEQUENCE   65 AA;  7688 MW;  55A4C306748E3D9A CRC64;
     MWKLWKFVDF RMTAVGFHIF FALIAFAVHF ACISSERFNW LEGAPAAEYY MDENPGIWKR
     TSYDG