ID B8HQS3_CYAP4 Unreviewed; 114 AA. AC B8HQS3; DT 03-MAR-2009, integrated into UniProtKB/TrEMBL. DT 03-MAR-2009, sequence version 1. DT 27-MAR-2024, entry version 62. DE RecName: Full=Ribulose bisphosphate carboxylase small subunit {ECO:0000256|HAMAP-Rule:MF_00859}; DE Short=RuBisCO small subunit {ECO:0000256|HAMAP-Rule:MF_00859}; GN Name=cbbS {ECO:0000256|HAMAP-Rule:MF_00859}; GN Synonyms=rbcS {ECO:0000256|HAMAP-Rule:MF_00859}; GN OrderedLocusNames=Cyan7425_3420 {ECO:0000313|EMBL:ACL45744.1}; OS Cyanothece sp. (strain PCC 7425 / ATCC 29141). OC Bacteria; Cyanobacteriota; Cyanophyceae; Gomontiellales; Cyanothecaceae; OC Cyanothece. OX NCBI_TaxID=395961 {ECO:0000313|EMBL:ACL45744.1}; RN [1] {ECO:0000313|EMBL:ACL45744.1} RP NUCLEOTIDE SEQUENCE. RC STRAIN=PCC 7425 {ECO:0000313|EMBL:ACL45744.1}; RG US DOE Joint Genome Institute; RA Lucas S., Copeland A., Lapidus A., Glavina del Rio T., Dalin E., Tice H., RA Bruce D., Goodwin L., Pitluck S., Sims D., Meineke L., Brettin T., RA Detter J.C., Han C., Larimer F., Land M., Hauser L., Kyrpides N., RA Ovchinnikova G., Liberton M., Stoeckel J., Banerjee A., Singh A., Page L., RA Sato H., Zhao L., Sherman L., Pakrasi H., Richardson P.; RT "Complete sequence of chromosome Cyanothece sp. PCC 7425."; RL Submitted (JAN-2009) 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:0000256|HAMAP-Rule:MF_00859}. CC -!- SUBUNIT: Heterohexadecamer of 8 large and 8 small subunits. CC {ECO:0000256|HAMAP-Rule:MF_00859}. CC -!- SUBCELLULAR LOCATION: Carboxysome {ECO:0000256|HAMAP-Rule:MF_00859}. 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:0000256|HAMAP-Rule:MF_00859}. CC -!- SIMILARITY: Belongs to the RuBisCO small chain family. CC {ECO:0000256|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; CP001344; ACL45744.1; -; Genomic_DNA. DR AlphaFoldDB; B8HQS3; -. DR STRING; 395961.Cyan7425_3420; -. DR KEGG; cyn:Cyan7425_3420; -. DR eggNOG; COG4451; Bacteria. DR HOGENOM; CLU_098114_2_0_3; -. DR OrthoDB; 9788955at2; -. 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 PRINTS; PR00152; RUBISCOSMALL. DR SMART; SM00961; RuBisCO_small; 1. DR SUPFAM; SSF55239; RuBisCO, small subunit; 1. PE 3: Inferred from homology; KW Bacterial microcompartment {ECO:0000256|HAMAP-Rule:MF_00859}; KW Calvin cycle {ECO:0000256|ARBA:ARBA00022567, ECO:0000256|HAMAP- KW Rule:MF_00859}; KW Carbon dioxide fixation {ECO:0000256|ARBA:ARBA00023300, ECO:0000256|HAMAP- KW Rule:MF_00859}; Carboxysome {ECO:0000256|HAMAP-Rule:MF_00859}; KW Lyase {ECO:0000313|EMBL:ACL45744.1}; KW Photorespiration {ECO:0000256|HAMAP-Rule:MF_00859}; KW Photosynthesis {ECO:0000256|HAMAP-Rule:MF_00859}. FT DOMAIN 9..106 FT /note="Ribulose bisphosphate carboxylase small subunit" FT /evidence="ECO:0000259|SMART:SM00961" SQ SEQUENCE 114 AA; 13351 MW; F765F58D5F0E6AF9 CRC64; MKTLPKERRY ETFSYLPPLS DAQIARQIQY TLDQGYIPAV EFNEDSNAET YYWTMWKLPL FNATSPQEVL NEVQQCRSEY SGSYIRVVAF DNVKQCQVMS FIVHKPNASG GYRY //