ID   RBS_SYNPW               Reviewed;         113 AA.
AC   P0A4S6; A5GJJ0; P96487;
DT   15-MAR-2005, integrated into UniProtKB/Swiss-Prot.
DT   15-MAR-2005, sequence version 1.
DT   25-MAY-2022, entry version 81.
DE   RecName: Full=Ribulose bisphosphate carboxylase small subunit {ECO:0000255|HAMAP-Rule:MF_00859};
DE            Short=RuBisCO small subunit {ECO:0000255|HAMAP-Rule:MF_00859};
GN   Name=cbbS {ECO:0000255|HAMAP-Rule:MF_00859};
GN   Synonyms=rbcS {ECO:0000255|HAMAP-Rule:MF_00859};
GN   OrderedLocusNames=SynWH7803_0679;
OS   Synechococcus sp. (strain WH7803).
OC   Bacteria; Cyanobacteria; Synechococcales; Synechococcaceae; Synechococcus;
OC   unclassified Synechococcus.
OX   NCBI_TaxID=32051;
RN   [1]
RP   NUCLEOTIDE SEQUENCE [GENOMIC DNA], AND INDUCTION.
RC   STRAIN=WH7803;
RX   PubMed=9002609; DOI=10.1007/bf00041394;
RA   Watson G.M., Tabita F.R.;
RT   "Regulation, unique gene organization, and unusual primary structure of
RT   carbon fixation genes from a marine phycoerythrin-containing
RT   cyanobacterium.";
RL   Plant Mol. Biol. 32:1103-1115(1996).
RN   [2]
RP   NUCLEOTIDE SEQUENCE [LARGE SCALE GENOMIC DNA].
RC   STRAIN=WH7803;
RG   Genoscope;
RL   Submitted (MAY-2006) to the EMBL/GenBank/DDBJ databases.
CC   -!- FUNCTION: RuBisCO catalyzes two reactions: the carboxylation of D-
CC       ribulose 1,5-bisphosphate, the primary event in carbon dioxide
CC       fixation, as well as the oxidative fragmentation of the pentose
CC       substrate in the photorespiration process. Both reactions occur
CC       simultaneously and in competition at the same active site. Although the
CC       small subunit is not catalytic it is essential for maximal activity.
CC       {ECO:0000255|HAMAP-Rule:MF_00859}.
CC   -!- SUBUNIT: Heterohexadecamer of 8 large and 8 small subunits.
CC       {ECO:0000255|HAMAP-Rule:MF_00859}.
CC   -!- SUBCELLULAR LOCATION: Carboxysome {ECO:0000255|HAMAP-Rule:MF_00859}.
CC   -!- INDUCTION: Transcribed during light cycle, reaching a peak after 6
CC       hours of illumination, mRNA becomes undetectable during the dark. Part
CC       of the csoS1-ccbL-ccbS operon. {ECO:0000269|PubMed:9002609}.
CC   -!- MISCELLANEOUS: The basic functional RuBisCO is composed of a large
CC       chain homodimer in a 'head-to-tail' conformation. In form I RuBisCO
CC       this homodimer is arranged in a barrel-like tetramer with the small
CC       subunits forming a tetrameric 'cap' on each end of the 'barrel'.
CC       {ECO:0000255|HAMAP-Rule:MF_00859}.
CC   -!- SIMILARITY: Belongs to the RuBisCO small chain family.
CC       {ECO:0000255|HAMAP-Rule:MF_00859}.
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DR   EMBL; U46156; AAB48081.1; -; Genomic_DNA.
DR   EMBL; CT971583; CAK23105.1; -; Genomic_DNA.
DR   RefSeq; WP_006043651.1; NC_009481.1.
DR   AlphaFoldDB; P0A4S6; -.
DR   SMR; P0A4S6; -.
DR   STRING; 32051.SynWH7803_0679; -.
DR   EnsemblBacteria; CAK23105; CAK23105; SynWH7803_0679.
DR   KEGG; syx:SynWH7803_0679; -.
DR   eggNOG; COG4451; Bacteria.
DR   HOGENOM; CLU_098114_2_0_3; -.
DR   OMA; KQCQVLS; -.
DR   OrthoDB; 1708389at2; -.
DR   Proteomes; UP000001566; Chromosome.
DR   GO; GO:0031470; C:carboxysome; IEA:UniProtKB-SubCell.
DR   GO; GO:0009853; P:photorespiration; IEA:UniProtKB-KW.
DR   GO; GO:0019253; P:reductive pentose-phosphate cycle; IEA:UniProtKB-KW.
DR   CDD; cd03527; RuBisCO_small; 1.
DR   Gene3D; 3.30.190.10; -; 1.
DR   HAMAP; MF_00859; RuBisCO_S_bact; 1.
DR   InterPro; IPR024681; RuBisCO_ssu.
DR   InterPro; IPR000894; RuBisCO_ssu_dom.
DR   InterPro; IPR036385; RuBisCO_ssu_sf.
DR   PANTHER; PTHR31262; PTHR31262; 1.
DR   Pfam; PF00101; RuBisCO_small; 1.
DR   SMART; SM00961; RuBisCO_small; 1.
DR   SUPFAM; SSF55239; SSF55239; 1.
PE   2: Evidence at transcript level;
KW   Bacterial microcompartment; Calvin cycle; Carbon dioxide fixation;
KW   Carboxysome; Photorespiration; Photosynthesis; Reference proteome.
FT   CHAIN           1..113
FT                   /note="Ribulose bisphosphate carboxylase small subunit"
FT                   /id="PRO_0000198625"
SQ   SEQUENCE   113 AA;  12943 MW;  8929415D336391F4 CRC64;
     MPFQSTVGDY QTVATLETFG FLPPMTQDEI YDQIAYIIAQ GWSPLVEHVH PSNSMATYWS
     YWKLPFFGEK DLNVVVSELE ACHRAYPDHH VRIVGYDAYT QSQGACFVVF EGR