ID   RBS2_HYDCU              Reviewed;         114 AA.
AC   Q31HD8;
DT   10-FEB-2021, integrated into UniProtKB/Swiss-Prot.
DT   06-DEC-2005, sequence version 1.
DT   27-MAR-2024, entry version 97.
DE   RecName: Full=Ribulose bisphosphate carboxylase small subunit 2 {ECO:0000255|HAMAP-Rule:MF_00859};
DE            Short=RuBisCO small subunit 2 {ECO:0000255|HAMAP-Rule:MF_00859};
DE   AltName: Full=Carboxysomal form I RuBisCO small subunit {ECO:0000303|PubMed:28115547};
GN   Name=cbbS2 {ECO:0000255|HAMAP-Rule:MF_00859};
GN   OrderedLocusNames=Tcr_0839;
OS   Hydrogenovibrio crunogenus (strain DSM 25203 / XCL-2) (Thiomicrospira
OS   crunogena).
OC   Bacteria; Pseudomonadota; Gammaproteobacteria; Thiotrichales;
OC   Piscirickettsiaceae; Hydrogenovibrio.
OX   NCBI_TaxID=317025;
RN   [1]
RP   NUCLEOTIDE SEQUENCE [LARGE SCALE GENOMIC DNA].
RC   STRAIN=DSM 25203 / XCL-2;
RX   PubMed=17105352; DOI=10.1371/journal.pbio.0040383;
RA   Scott K.M., Sievert S.M., Abril F.N., Ball L.A., Barrett C.J., Blake R.A.,
RA   Boller A.J., Chain P.S.G., Clark J.A., Davis C.R., Detter C., Do K.F.,
RA   Dobrinski K.P., Faza B.I., Fitzpatrick K.A., Freyermuth S.K., Harmer T.L.,
RA   Hauser L.J., Huegler M., Kerfeld C.A., Klotz M.G., Kong W.W., Land M.,
RA   Lapidus A., Larimer F.W., Longo D.L., Lucas S., Malfatti S.A., Massey S.E.,
RA   Martin D.D., McCuddin Z., Meyer F., Moore J.L., Ocampo L.H. Jr., Paul J.H.,
RA   Paulsen I.T., Reep D.K., Ren Q., Ross R.L., Sato P.Y., Thomas P.,
RA   Tinkham L.E., Zeruth G.T.;
RT   "The genome of deep-sea vent chemolithoautotroph Thiomicrospira crunogena
RT   XCL-2.";
RL   PLoS Biol. 4:1-17(2006).
RN   [2]
RP   FUNCTION, AND SUBCELLULAR LOCATION.
RC   STRAIN=DSM 25203 / XCL-2;
RX   PubMed=18974784; DOI=10.1371/journal.pone.0003570;
RA   Menon B.B., Dou Z., Heinhorst S., Shively J.M., Cannon G.C.;
RT   "Halothiobacillus neapolitanus carboxysomes sequester heterologous and
RT   chimeric RubisCO species.";
RL   PLoS ONE 3:e3570-e3570(2008).
RN   [3]
RP   BIOPHYSICOCHEMICAL PROPERTIES, AND SUBCELLULAR LOCATION.
RC   STRAIN=DSM 25203 / XCL-2;
RX   PubMed=26581415; DOI=10.1007/s00203-015-1172-6;
RG   USF MCB4404L 2012;
RA   Menning K.J., Menon B.B., Fox G., Scott K.M.;
RT   "Dissolved inorganic carbon uptake in Thiomicrospira crunogena XCL-2 is
RT   Deltap- and ATP-sensitive and enhances RubisCO-mediated carbon fixation.";
RL   Arch. Microbiol. 198:149-159(2016).
RN   [4]
RP   INDUCTION.
RX   PubMed=28115547; DOI=10.1128/jb.00871-16;
RG   USF MCB4404L;
RA   Mangiapia M., Brown T.W., Chaput D., Haller E., Harmer T.L., Hashemy Z.,
RA   Keeley R., Leonard J., Mancera P., Nicholson D., Stevens S., Wanjugi P.,
RA   Zabinski T., Pan C., Scott K.M.;
RT   "Proteomic and Mutant Analysis of the CO2 Concentrating Mechanism of
RT   Hydrothermal Vent Chemolithoautotroph Thiomicrospira crunogena.";
RL   J. Bacteriol. 199:0-0(2017).
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 (Probable). Although the small subunit is not
CC       catalytic it is essential for maximal activity.
CC       {ECO:0000305|PubMed:18974784}.
CC   -!- FUNCTION: Replacing the endogenous type I ccbLS genes in H.neapolitanus
CC       with this carboxysomally targeted enzyme reconstitutes RuBisCO with
CC       about 25% of normal activity; the active enzyme is targeted to
CC       carboxysomes (PubMed:18974784). {ECO:0000269|PubMed:18974784}.
CC   -!- BIOPHYSICOCHEMICAL PROPERTIES:
CC       Kinetic parameters:
CC         KM=276 uM for CO(2) {ECO:0000269|PubMed:26581415};
CC         Vmax=252 nmol/min/mg enzyme {ECO:0000269|PubMed:26581415};
CC         Note=kcat is 0.27 sec(-1) for holoenzyme.
CC         {ECO:0000269|PubMed:26581415};
CC       pH dependence:
CC         Optimum pH is 8.0. {ECO:0000269|PubMed:26581415};
CC   -!- SUBUNIT: Heterohexadecamer of 8 large and 8 small subunits. Forms a
CC       CsoS2-CsoS1-RuBisCO complex. {ECO:0000250|UniProtKB:P45686,
CC       ECO:0000255|HAMAP-Rule:MF_00859}.
CC   -!- SUBCELLULAR LOCATION: Carboxysome {ECO:0000269|PubMed:26581415,
CC       ECO:0000305|PubMed:17105352, ECO:0000305|PubMed:18974784}. Note=This
CC       bacterium makes alpha-type carboxysomes. {ECO:0000305}.
CC   -!- INDUCTION: Induced by growth in low levels of dissolved inorganic
CC       carbon (at protein level). {ECO:0000269|PubMed:28115547}.
CC   -!- MISCELLANEOUS: Encoded in a cso-type operon.
CC       {ECO:0000269|PubMed:17105352}.
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; CP000109; ABB41435.1; -; Genomic_DNA.
DR   AlphaFoldDB; Q31HD8; -.
DR   SMR; Q31HD8; -.
DR   STRING; 317025.Tcr_0839; -.
DR   KEGG; tcx:Tcr_0839; -.
DR   eggNOG; COG4451; Bacteria.
DR   HOGENOM; CLU_098114_2_0_6; -.
DR   OrthoDB; 9788955at2; -.
DR   GO; GO:0031470; C:carboxysome; 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   Pfam; PF00101; RuBisCO_small; 1.
DR   SMART; SM00961; RuBisCO_small; 1.
DR   SUPFAM; SSF55239; RuBisCO, small subunit; 1.
PE   1: Evidence at protein level;
KW   Bacterial microcompartment; Calvin cycle; Carbon dioxide fixation;
KW   Carboxysome.
FT   CHAIN           1..114
FT                   /note="Ribulose bisphosphate carboxylase small subunit 2"
FT                   /id="PRO_0000452047"
SQ   SEQUENCE   114 AA;  13396 MW;  44DE3D5C93F33DC9 CRC64;
     MSISQIDDYR TQYTLETFSF LPELTADEIY DQIVYIINQG WSPALEHEEP AKASDHYWGM
     WKLPMFGTRD PNEVLAEIDA CRQAYPNHLI RLVGYDNYTQ CQGHNFVVYR PRGM
//