ID K9SDQ7_9CYAN Unreviewed; 113 AA. AC K9SDQ7; DT 06-MAR-2013, integrated into UniProtKB/TrEMBL. DT 06-MAR-2013, sequence version 1. DT 24-JAN-2024, entry version 37. 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 ORFNames=GEI7407_3808 {ECO:0000313|EMBL:AFY68275.1}; OS Geitlerinema sp. PCC 7407. OC Bacteria; Cyanobacteriota; Cyanophyceae; Geitlerinematales; OC Geitlerinemataceae; Geitlerinema. OX NCBI_TaxID=1173025 {ECO:0000313|EMBL:AFY68275.1, ECO:0000313|Proteomes:UP000010383}; RN [1] {ECO:0000313|EMBL:AFY68275.1, ECO:0000313|Proteomes:UP000010383} RP NUCLEOTIDE SEQUENCE [LARGE SCALE GENOMIC DNA]. RC STRAIN=PCC 7407 {ECO:0000313|EMBL:AFY68275.1, RC ECO:0000313|Proteomes:UP000010383}; RG US DOE Joint Genome Institute; RA Gugger M., Coursin T., Rippka R., Tandeau De Marsac N., Huntemann M., RA Wei C.-L., Han J., Detter J.C., Han C., Tapia R., Davenport K., RA Daligault H., Erkkila T., Gu W., Munk A.C.C., Teshima H., Xu Y., Chain P., RA Chen A., Krypides N., Mavromatis K., Markowitz V., Szeto E., Ivanova N., RA Mikhailova N., Ovchinnikova G., Pagani I., Pati A., Goodwin L., Peters L., RA Pitluck S., Woyke T., Kerfeld C.; RT "Finished genome of Geitlerinema sp. PCC 7407."; RL Submitted (MAY-2012) 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; CP003591; AFY68275.1; -; Genomic_DNA. DR RefSeq; WP_015173839.1; NC_019703.1. DR AlphaFoldDB; K9SDQ7; -. DR STRING; 1173025.GEI7407_3808; -. DR KEGG; gei:GEI7407_3808; -. DR PATRIC; fig|1173025.3.peg.4262; -. DR eggNOG; COG4451; Bacteria. DR HOGENOM; CLU_098114_2_0_3; -. DR OrthoDB; 9788955at2; -. DR Proteomes; UP000010383; 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 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:AFY68275.1}; KW Photorespiration {ECO:0000256|HAMAP-Rule:MF_00859}; KW Photosynthesis {ECO:0000256|HAMAP-Rule:MF_00859}; KW Reference proteome {ECO:0000313|Proteomes:UP000010383}. FT DOMAIN 9..106 FT /note="Ribulose bisphosphate carboxylase small subunit" FT /evidence="ECO:0000259|SMART:SM00961" SQ SEQUENCE 113 AA; 13284 MW; 960C15F1E75A76C0 CRC64; MQTLKKERRF ETLSYLPPLS DAQIARQVQY ILDQGYFAAV EFNETSNPTE VYWTMWKLPL FSANSVQEVL NEVQQCRSEY PNCYIRVIGF DNIKQCQTLS FIVHKPNSGG YRY //