ID RBS_CYAM1 Reviewed; 138 AA. AC O22024; DT 15-DEC-1998, integrated into UniProtKB/Swiss-Prot. DT 01-JAN-1998, sequence version 1. DT 24-JAN-2024, entry version 110. 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=rbcS {ECO:0000255|HAMAP-Rule:MF_00859}; OS Cyanidioschyzon merolae (strain NIES-3377 / 10D) (Unicellular red alga). OG Plastid; Chloroplast. OC Eukaryota; Rhodophyta; Bangiophyceae; Cyanidiales; Cyanidiaceae; OC Cyanidioschyzon. OX NCBI_TaxID=280699; RN [1] RP NUCLEOTIDE SEQUENCE [GENOMIC DNA]. RA Ohta N., Sato N., Ueda K., Kuroiwa T.; RT "Analysis of a plastid gene cluster reveals a close relationship between RT Cyanidioschyzon and Cyanidium."; RL J. Plant Res. 110:235-245(1997). RN [2] RP NUCLEOTIDE SEQUENCE [LARGE SCALE GENOMIC DNA]. RC STRAIN=NIES-3377 / 10D; RX PubMed=12755171; DOI=10.1093/dnares/10.2.67; RA Ohta N., Matsuzaki M., Misumi O., Miyagishima S.-Y., Nozaki H., Tanaka K., RA Shin-i T., Kohara Y., Kuroiwa T.; RT "Complete sequence and analysis of the plastid genome of the unicellular RT red alga Cyanidioschyzon merolae."; RL DNA Res. 10:67-77(2003). 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: Plastid, chloroplast {ECO:0000255|HAMAP- CC Rule:MF_00859}. CC -!- MISCELLANEOUS: In this alga, in contrast to plants, the small subunit CC is encoded in the chloroplast. 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; D63675; BAA22820.1; -; Genomic_DNA. DR EMBL; AB002583; BAC76108.1; -; Genomic_DNA. DR RefSeq; NP_848946.1; NC_004799.1. DR AlphaFoldDB; O22024; -. DR SMR; O22024; -. DR STRING; 280699.O22024; -. DR EnsemblPlants; CMV014CT; CMV014CT; CMV014C. DR GeneID; 844965; -. DR Gramene; CMV014CT; CMV014CT; CMV014C. DR KEGG; cme:CymeCp014; -. DR eggNOG; ENOG502QTPB; Eukaryota. DR HOGENOM; CLU_098114_2_0_1; -. DR Proteomes; UP000007014; Chloroplast. DR GO; GO:0009507; C:chloroplast; IEA:UniProtKB-SubCell. DR GO; GO:0016984; F:ribulose-bisphosphate carboxylase activity; IEA:UniProtKB-UniRule. 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 PANTHER; PTHR31262:SF23; RIBULOSE BISPHOSPHATE CARBOXYLASE SMALL SUBUNIT; 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 Calvin cycle; Carbon dioxide fixation; Chloroplast; Photorespiration; KW Photosynthesis; Plastid; Reference proteome. FT CHAIN 1..138 FT /note="Ribulose bisphosphate carboxylase small subunit" FT /id="PRO_0000198593" SQ SEQUENCE 138 AA; 16225 MW; 584F64F1709104A8 CRC64; MRVTQGTFCY LPDLTDEQIR KQIQYAINQG WAVSVEYTDD PHPRNSYWEM WGLPLFDVKD PATIMFEVQE CRKQFPNHYI KVLAFNSTKG IESTALSFIV NRPANEPGFV LRRIESNDRV QRYQIHSYAT EKPEGSRY //