ID   RBS_OLILU               Reviewed;         139 AA.
AC   P14961;
DT   01-APR-1990, integrated into UniProtKB/Swiss-Prot.
DT   01-APR-1990, sequence version 1.
DT   25-MAY-2022, entry version 100.
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   Olisthodiscus luteus (Marine phytoflagellate).
OG   Plastid; Chloroplast.
OC   Eukaryota; Sar; Stramenopiles; Ochrophyta; Olisthodiscophyceae;
OC   Olisthodiscaceae; Olisthodiscus.
OX   NCBI_TaxID=83000;
RN   [1]
RP   NUCLEOTIDE SEQUENCE [GENOMIC DNA].
RC   STRAIN=Carter;
RX   PubMed=2740337; DOI=10.1073/pnas.86.13.4996;
RA   Boczar B.A., Delaney T.P., Cattolico R.A.;
RT   "Gene for the ribulose-1,5-bisphosphate carboxylase small subunit protein
RT   of the marine chromophyte Olisthodiscus luteus is similar to that of a
RT   chemoautotrophic bacterium.";
RL   Proc. Natl. Acad. Sci. U.S.A. 86:4996-4999(1989).
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}.
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DR   EMBL; M24288; AAA84532.1; -; Genomic_DNA.
DR   PIR; A32940; RKMLS.
DR   AlphaFoldDB; P14961; -.
DR   SMR; P14961; -.
DR   GO; GO:0009507; C:chloroplast; IEA:UniProtKB-SubCell.
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   3: Inferred from homology;
KW   Calvin cycle; Carbon dioxide fixation; Chloroplast; Photorespiration;
KW   Photosynthesis; Plastid.
FT   CHAIN           1..139
FT                   /note="Ribulose bisphosphate carboxylase small subunit"
FT                   /id="PRO_0000198601"
SQ   SEQUENCE   139 AA;  15958 MW;  2ACB3A875F8344A5 CRC64;
     MRLTQGAFSY LPDLTDAQII KQIDYCLSRG WSVGVEWTDD PHPRNAYWEL WGLPLFDVKD
     SSAILYEVNE CRRLNPEGYI KLVAFNAARG TESSASAFIV QRPKSEPGFY LERTEAEGRM
     IRYTIHSYAV ARNPEGSRY