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 27-MAR-2024, entry version 86. 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; Cyanobacteriota; Cyanophyceae; Synechococcales; Synechococcaceae; OC 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}. CC --------------------------------------------------------------------------- CC Copyrighted by the UniProt Consortium, see https://www.uniprot.org/terms CC Distributed under the Creative Commons Attribution (CC BY 4.0) License CC --------------------------------------------------------------------------- DR EMBL; U46156; AAB48081.1; -; Genomic_DNA. DR EMBL; CT971583; CAK23105.1; -; Genomic_DNA. DR AlphaFoldDB; P0A4S6; -. DR SMR; P0A4S6; -. DR STRING; 32051.SynWH7803_0679; -. DR KEGG; syx:SynWH7803_0679; -. DR eggNOG; COG4451; Bacteria. DR HOGENOM; CLU_098114_2_0_3; -. DR OrthoDB; 9788955at2; -. DR Proteomes; UP000001566; Chromosome. DR GO; GO:0031470; C:carboxysome; IEA:UniProtKB-SubCell. DR GO; GO:0016984; F:ribulose-bisphosphate carboxylase activity; IEA:UniProtKB-UniRule. DR GO; GO:0009853; P:photorespiration; IEA:UniProtKB-KW. DR GO; GO:0019253; P:reductive pentose-phosphate cycle; IEA:UniProtKB-UniRule. DR CDD; cd03527; RuBisCO_small; 1. DR Gene3D; 3.30.190.10; Ribulose bisphosphate carboxylase, small subunit; 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; RIBULOSE BISPHOSPHATE CARBOXYLASE SMALL CHAIN 1, CHLOROPLASTIC; 1. DR Pfam; PF00101; RuBisCO_small; 1. DR SMART; SM00961; RuBisCO_small; 1. DR SUPFAM; SSF55239; RuBisCO, small subunit; 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 //