ID   RBS_TOBAC               Reviewed;         180 AA.
AC   P69249; P00866; P00867; P26666;
DT   21-JUL-1986, integrated into UniProtKB/Swiss-Prot.
DT   21-JUL-1986, sequence version 1.
DT   27-MAR-2024, entry version 97.
DE   RecName: Full=Ribulose bisphosphate carboxylase small subunit, chloroplastic {ECO:0000255|HAMAP-Rule:MF_00860, ECO:0000303|PubMed:3681999};
DE            Short=RuBisCO small subunit {ECO:0000255|HAMAP-Rule:MF_00860, ECO:0000303|PubMed:3681999};
DE   AltName: Full=TSSU3-8 {ECO:0000303|PubMed:3684569};
DE   Flags: Precursor;
GN   Name=RBCS {ECO:0000255|HAMAP-Rule:MF_00860,
GN   ECO:0000303|PubMed:3681999};
OS   Nicotiana tabacum (Common tobacco).
OC   Eukaryota; Viridiplantae; Streptophyta; Embryophyta; Tracheophyta;
OC   Spermatophyta; Magnoliopsida; eudicotyledons; Gunneridae; Pentapetalae;
OC   asterids; lamiids; Solanales; Solanaceae; Nicotianoideae; Nicotianeae;
OC   Nicotiana.
OX   NCBI_TaxID=4097;
RN   [1]
RP   NUCLEOTIDE SEQUENCE [GENOMIC DNA].
RX   PubMed=4000958; DOI=10.1093/nar/13.7.2373;
RA   Mazur B.J., Chui C.-F.;
RT   "Sequence of a genomic DNA clone for the small subunit of ribulose bis-
RT   phosphate carboxylase-oxygenase from tobacco.";
RL   Nucleic Acids Res. 13:2373-2386(1985).
RN   [2]
RP   PROTEIN SEQUENCE OF 58-180.
RA   Mueller K.-D., Salnikow J., Vater J.;
RT   "Amino acid sequence of the small subunit of D-ribulose bisphosphate
RT   carboxylase/oxygenase from Nicotiana tabacum.";
RL   Biochim. Biophys. Acta 742:78-83(1983).
RN   [3]
RP   NUCLEOTIDE SEQUENCE [GENOMIC DNA] OF 1-101.
RX   PubMed=3684569; DOI=10.1093/nar/15.21.8661;
RA   O'Neal J.K., Pokalsky A.R., Kiehne K.L., Shewmaker C.K.;
RT   "Isolation of tobacco SSU genes: characterization of a transcriptionally
RT   active pseudogene.";
RL   Nucleic Acids Res. 15:8661-8677(1987).
RN   [4] {ECO:0007744|PDB:4RUB}
RP   X-RAY CRYSTALLOGRAPHY (2.7 ANGSTROMS) OF 58-180 OF ACTIVATED HOLOENZYME,
RP   FUNCTION, CATALYTIC ACTIVITY, AND SUBUNIT.
RX   PubMed=3681999; DOI=10.1016/0022-2836(87)90129-x;
RA   Suh S.W., Cascio D., Chapman M.S., Eisenberg D.;
RT   "A crystal form of ribulose-1,5-bisphosphate carboxylase/oxygenase from
RT   Nicotiana tabacum in the activated state.";
RL   J. Mol. Biol. 197:363-365(1987).
RN   [5] {ECO:0007744|PDB:3RUB}
RP   X-RAY CRYSTALLOGRAPHY (2.0 ANGSTROMS) OF 58-180 OF UNACTIVATED HOLOENZYME,
RP   AND SUBUNIT.
RC   STRAIN=cv. Turkish samsun;
RX   PubMed=1512238; DOI=10.1016/s0021-9258(18)41881-9;
RA   Curmi P.M.G., Cascio D., Sweet R.M., Eisenberg D., Schreuder H.;
RT   "Crystal structure of the unactivated form of ribulose-1,5-bisphosphate
RT   carboxylase/oxygenase from tobacco refined at 2.0-A resolution.";
RL   J. Biol. Chem. 267:16980-16989(1992).
RN   [6] {ECO:0007744|PDB:1EJ7}
RP   X-RAY CRYSTALLOGRAPHY (2.45 ANGSTROMS) OF 58-180 OF UNACTIVATED HOLOENZYME,
RP   AND SUBUNIT.
RC   STRAIN=cv. Wisconsin-38;
RX   PubMed=10801357; DOI=10.1006/jmbi.2000.3724;
RA   Duff A.P., Andrews T.J., Curmi P.M.G.;
RT   "The transition between the open and closed states of rubisco is triggered
RT   by the inter-phosphate distance of the bound bisphosphate.";
RL   J. Mol. Biol. 298:903-916(2000).
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 (PubMed:3681999). Both reactions occur simultaneously and in
CC       competition at the same active site (Probable). Involved in antiviral
CC       defenses (By similarity). {ECO:0000250|UniProtKB:A0A0S4IJL0,
CC       ECO:0000269|PubMed:3681999, ECO:0000305}.
CC   -!- SUBUNIT: Heterohexadecamer of 8 large and 8 small subunits.
CC       {ECO:0000255|HAMAP-Rule:MF_00860, ECO:0000269|PubMed:1512238,
CC       ECO:0000269|PubMed:3681999}.
CC   -!- SUBUNIT: (Microbial infection) Binds to tobamovirus movement protein;
CC       this interaction seems required for viral systemic movement.
CC       {ECO:0000250|UniProtKB:A0A0S4IJL0, ECO:0000305}.
CC   -!- INTERACTION:
CC       P69249; O81283: TOC159; Xeno; NbExp=5; IntAct=EBI-1766821, EBI-639063;
CC       P69249; Q38906: TOC34; Xeno; NbExp=6; IntAct=EBI-1766821, EBI-1766808;
CC   -!- SUBCELLULAR LOCATION: Plastid, chloroplast {ECO:0000255|HAMAP-
CC       Rule:MF_00860, ECO:0000305}.
CC   -!- SUBCELLULAR LOCATION: Cell junction, plasmodesma
CC       {ECO:0000250|UniProtKB:A0A0S4IJL0}. Note=(Microbial infection) May be
CC       present in virus replication complexes (VRCs) of tobamovirus infected
CC       cells. {ECO:0000250|UniProtKB:A0A0S4IJL0}.
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_00860, ECO:0000269|PubMed:1512238,
CC       ECO:0000269|PubMed:3681999}.
CC   -!- SIMILARITY: Belongs to the RuBisCO small chain family.
CC       {ECO:0000255|HAMAP-Rule:MF_00860}.
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DR   EMBL; X02353; CAA26208.1; -; Genomic_DNA.
DR   EMBL; M32419; AAA34116.1; -; Genomic_DNA.
DR   PIR; A22934; RKNTSP.
DR   RefSeq; XP_016440853.1; XM_016585367.1.
DR   RefSeq; XP_016481946.1; XM_016626460.1.
DR   PDB; 1EJ7; X-ray; 2.45 A; S=58-180.
DR   PDB; 1RLC; X-ray; 2.70 A; S=58-180.
DR   PDB; 1RLD; X-ray; 2.50 A; S/T=58-180.
DR   PDB; 3RUB; X-ray; 2.00 A; S=58-180.
DR   PDB; 4RUB; X-ray; 2.70 A; S/T/U/V=58-180.
DR   PDBsum; 1EJ7; -.
DR   PDBsum; 1RLC; -.
DR   PDBsum; 1RLD; -.
DR   PDBsum; 3RUB; -.
DR   PDBsum; 4RUB; -.
DR   AlphaFoldDB; P69249; -.
DR   SMR; P69249; -.
DR   DIP; DIP-40635N; -.
DR   IntAct; P69249; 4.
DR   MINT; P69249; -.
DR   STRING; 4097.P69249; -.
DR   PaxDb; 4097-P69249; -.
DR   GeneID; 107766567; -.
DR   GeneID; 107802883; -.
DR   KEGG; nta:107766567; -.
DR   KEGG; nta:107802883; -.
DR   OMA; RKNWVPC; -.
DR   OrthoDB; 5482775at2759; -.
DR   PhylomeDB; P69249; -.
DR   BRENDA; 4.1.1.39; 3645.
DR   SABIO-RK; P69249; -.
DR   EvolutionaryTrace; P69249; -.
DR   Proteomes; UP000084051; Unplaced.
DR   GO; GO:0009507; C:chloroplast; IEA:UniProtKB-SubCell.
DR   GO; GO:0009506; C:plasmodesma; IEA:UniProtKB-SubCell.
DR   GO; GO:0016984; F:ribulose-bisphosphate carboxylase activity; IEA:UniProtKB-UniRule.
DR   GO; GO:0051607; P:defense response to virus; IEA:UniProtKB-KW.
DR   GO; GO:0009853; P:photorespiration; IEA:UniProtKB-KW.
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; IPR024680; RuBisCO_ssu_N.
DR   InterPro; IPR036385; RuBisCO_ssu_sf.
DR   PANTHER; PTHR31262; RIBULOSE BISPHOSPHATE CARBOXYLASE SMALL CHAIN 1, CHLOROPLASTIC; 1.
DR   PANTHER; PTHR31262:SF10; RIBULOSE BISPHOSPHATE CARBOXYLASE SMALL SUBUNIT, CHLOROPLASTIC 2; 1.
DR   Pfam; PF12338; RbcS; 1.
DR   Pfam; PF00101; RuBisCO_small; 1.
DR   PRINTS; PR00152; RUBISCOSMALL.
DR   SMART; SM00961; RuBisCO_small; 1.
DR   SUPFAM; SSF55239; RuBisCO, small subunit; 1.
PE   1: Evidence at protein level;
KW   3D-structure; Antiviral defense; Calvin cycle; Carbon dioxide fixation;
KW   Cell junction; Chloroplast; Direct protein sequencing; Photorespiration;
KW   Photosynthesis; Plastid; Reference proteome; Transit peptide.
FT   TRANSIT         1..57
FT                   /note="Chloroplast"
FT                   /evidence="ECO:0000269|Ref.2"
FT   TRANSIT         1..56
FT                   /note="Chloroplast"
FT                   /evidence="ECO:0000255|HAMAP-Rule:MF_00860"
FT   CHAIN           57..180
FT                   /note="Ribulose bisphosphate carboxylase small subunit,
FT                   chloroplastic"
FT                   /evidence="ECO:0000255|HAMAP-Rule:MF_00860"
FT                   /id="PRO_0000031560"
FT   CONFLICT        87..88
FT                   /note="VE -> PD (in Ref. 2; AA sequence)"
FT                   /evidence="ECO:0000305"
FT   CONFLICT        93
FT                   /note="N -> D (in Ref. 2; AA sequence)"
FT                   /evidence="ECO:0000305"
FT   CONFLICT        153
FT                   /note="Q -> E (in Ref. 2; AA sequence)"
FT                   /evidence="ECO:0000305"
FT   STRAND          63..65
FT                   /evidence="ECO:0007829|PDB:3RUB"
FT   TURN            71..74
FT                   /evidence="ECO:0007829|PDB:3RUB"
FT   HELIX           80..92
FT                   /evidence="ECO:0007829|PDB:3RUB"
FT   STRAND          96..104
FT                   /evidence="ECO:0007829|PDB:3RUB"
FT   STRAND          125..128
FT                   /evidence="ECO:0007829|PDB:3RUB"
FT   HELIX           137..150
FT                   /evidence="ECO:0007829|PDB:3RUB"
FT   STRAND          154..162
FT                   /evidence="ECO:0007829|PDB:3RUB"
FT   TURN            163..166
FT                   /evidence="ECO:0007829|PDB:3RUB"
FT   STRAND          167..175
FT                   /evidence="ECO:0007829|PDB:3RUB"
SQ   SEQUENCE   180 AA;  20311 MW;  26CF3F48EF0860AD CRC64;
     MASSVLSSAA VATRSNVAQA NMVAPFTGLK SAASFPVSRK QNLDITSIAS NGGRVQCMQV
     WPPINKKKYE TLSYLPDLSQ EQLLSEVEYL LKNGWVPCLE FETEHGFVYR ENNKSPGYYD
     GRYWTMWKLP MFGCTDATQV LAEVEEAKKA YPQAWIRIIG FDNVRQVQCI SFIAYKPEGY
//