ID   RBS_PROMM               Reviewed;         113 AA.
AC   Q7V6F9;
DT   10-FEB-2021, integrated into UniProtKB/Swiss-Prot.
DT   01-OCT-2003, sequence version 1.
DT   25-MAY-2022, entry version 101.
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=cbbS {ECO:0000255|HAMAP-Rule:MF_00859, ECO:0000303|PubMed:25826651};
GN   Synonyms=rbcS {ECO:0000255|HAMAP-Rule:MF_00859};
GN   OrderedLocusNames=PMT_1204;
OS   Prochlorococcus marinus (strain MIT 9313).
OC   Bacteria; Cyanobacteria; Synechococcales; Prochlorococcaceae;
OC   Prochlorococcus.
OX   NCBI_TaxID=74547;
RN   [1]
RP   NUCLEOTIDE SEQUENCE [LARGE SCALE GENOMIC DNA].
RC   STRAIN=MIT 9313;
RX   PubMed=12917642; DOI=10.1038/nature01947;
RA   Rocap G., Larimer F.W., Lamerdin J.E., Malfatti S., Chain P., Ahlgren N.A.,
RA   Arellano A., Coleman M., Hauser L., Hess W.R., Johnson Z.I., Land M.L.,
RA   Lindell D., Post A.F., Regala W., Shah M., Shaw S.L., Steglich C.,
RA   Sullivan M.B., Ting C.S., Tolonen A., Webb E.A., Zinser E.R.,
RA   Chisholm S.W.;
RT   "Genome divergence in two Prochlorococcus ecotypes reflects oceanic niche
RT   differentiation.";
RL   Nature 424:1042-1047(2003).
RN   [2]
RP   SUBUNIT.
RC   STRAIN=MIT 9313;
RX   PubMed=25826651; DOI=10.3390/life5021141;
RA   Cai F., Dou Z., Bernstein S.L., Leverenz R., Williams E.B., Heinhorst S.,
RA   Shively J., Cannon G.C., Kerfeld C.A.;
RT   "Advances in Understanding Carboxysome Assembly in Prochlorococcus and
RT   Synechococcus Implicate CsoS2 as a Critical Component.";
RL   Life 5:1141-1171(2015).
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. Forms a
CC       CsoS2-CsoS1-RuBisCO complex (Probable). {ECO:0000255|HAMAP-
CC       Rule:MF_00859, ECO:0000305|PubMed:25826651}.
CC   -!- SUBCELLULAR LOCATION: Carboxysome {ECO:0000255|HAMAP-Rule:MF_00859,
CC       ECO:0000305|PubMed:25826651}. Note=This bacterium makes alpha-type
CC       carboxysomes. {ECO:0000269|PubMed:25826651}.
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; BX548175; CAE21379.1; -; Genomic_DNA.
DR   RefSeq; WP_011130575.1; NC_005071.1.
DR   AlphaFoldDB; Q7V6F9; -.
DR   SMR; Q7V6F9; -.
DR   STRING; 74547.PMT_1204; -.
DR   EnsemblBacteria; CAE21379; CAE21379; PMT_1204.
DR   KEGG; pmt:PMT_1204; -.
DR   eggNOG; COG4451; Bacteria.
DR   HOGENOM; CLU_098114_2_0_3; -.
DR   OMA; KQCQVLS; -.
DR   OrthoDB; 1708389at2; -.
DR   Proteomes; UP000001423; Chromosome.
DR   GO; GO:0031470; C:carboxysome; IEA:UniProtKB-SubCell.
DR   GO; GO:0009853; P:photorespiration; IEA:UniProtKB-KW.
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   1: Evidence at protein level;
KW   Bacterial microcompartment; Calvin cycle; Carbon dioxide fixation;
KW   Carboxysome; Photorespiration; Photosynthesis; Reference proteome.
FT   CHAIN           1..113
FT                   /note="Ribulose bisphosphate carboxylase small subunit"
FT                   /id="PRO_0000452048"
SQ   SEQUENCE   113 AA;  12991 MW;  8F4C964FBA72A37C CRC64;
     MPFQSTVGDY QTVATLETFG FLPPMTQDEI YDQIAYIIAQ GWSPVIEHVH PSGSMQTYWS
     YWKLPFFGEK DLNMVVSELE ACHRAYPDHH VRMVGYDAYT QSQGTAFVVF EGR