ID   RBS_CYAPA               Reviewed;         106 AA.
AC   P18062;
DT   01-NOV-1990, integrated into UniProtKB/Swiss-Prot.
DT   01-NOV-1990, sequence version 1.
DT   25-MAY-2022, entry version 90.
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   Cyanophora paradoxa.
OG   Plastid; Cyanelle.
OC   Eukaryota; Glaucocystophyceae; Cyanophoraceae; Cyanophora.
OX   NCBI_TaxID=2762;
RN   [1]
RP   NUCLEOTIDE SEQUENCE [GENOMIC DNA].
RA   Starnes S.M., Lambert D.H., Maxwell E.S., Stevens S.E. Jr., Porter R.D.,
RA   Shively J.M.;
RT   "Cotranscription of the large and small subunit genes of ribulose-1,5-
RT   bisphosphate carboxylase/oxygenase in Cyanophora paradoxa.";
RL   FEMS Microbiol. Lett. 28:165-169(1985).
RN   [2]
RP   NUCLEOTIDE SEQUENCE [LARGE SCALE GENOMIC DNA].
RC   STRAIN=UTEX LB 555 / Pringsheim;
RA   Stirewalt V.L., Michalowski C.B., Loeffelhardt W., Bohnert H.J.,
RA   Bryant D.A.;
RT   "Nucleotide sequence of the cyanelle DNA from Cyanophora paradoxa.";
RL   Plant Mol. Biol. Rep. 13:327-332(1995).
RN   [3]
RP   NUCLEOTIDE SEQUENCE [LARGE SCALE GENOMIC DNA].
RC   STRAIN=UTEX LB 555 / Pringsheim;
RA   Loeffelhardt W., Stirewalt V.L., Michalowski C.B., Annarella M.,
RA   Farley J.Y., Schluchter W.M., Chung S., Newmann-Spallart C., Steiner J.M.,
RA   Jakowitsch J., Bohnert H.J., Bryant D.A.;
RT   "The complete sequence of the cyanelle genome of Cyanophora paradoxa: the
RT   genetic complexity of a primitive plastid.";
RL   (In) Schenk H.E.A., Herrmann R., Jeon K.W., Mueller N.E., Schwemmler W.
RL   (eds.);
RL   Eukaryotism and symbiosis, pp.40-48, Springer-Verlag, Heidelberg (1997).
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. Both reactions occur simultaneously and in competition at
CC       the same active site. Although the small subunit is not catalytic it is
CC       essential for maximal activity. {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, cyanelle.
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; M35728; AAA31702.1; -; Genomic_DNA.
DR   EMBL; U30821; AAA81270.1; -; Genomic_DNA.
DR   PIR; T06927; T06927.
DR   RefSeq; NP_043239.2; NC_001675.1.
DR   AlphaFoldDB; P18062; -.
DR   SMR; P18062; -.
DR   GeneID; 801664; -.
DR   GO; GO:0009842; C:cyanelle; 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; Cyanelle; Photorespiration;
KW   Photosynthesis; Plastid.
FT   CHAIN           1..106
FT                   /note="Ribulose bisphosphate carboxylase small subunit"
FT                   /id="PRO_0000198594"
SQ   SEQUENCE   106 AA;  12336 MW;  6919A8D3008558D0 CRC64;
     MQLRVERKFE TFSYLPPLND QQIARQLQYA LSNGYSPAIE FSFTGKAEDL VWTLWKLPLF
     GAQSPEEVLS EIQACKQQFP NAYIRVVAFD SIRQVQTLMF LVYKPL