ID   A9PHQ1_POPTR            Unreviewed;       181 AA.
AC   A9PHQ1;
DT   05-FEB-2008, integrated into UniProtKB/TrEMBL.
DT   05-FEB-2008, sequence version 1.
DT   02-SEP-2026, entry version 119.
DE   RecName: Full=Ribulose bisphosphate carboxylase small subunit, chloroplastic {ECO:0000256|HAMAP-Rule:MF_00860};
DE            Short=RuBisCO small subunit {ECO:0000256|HAMAP-Rule:MF_00860};
GN   Name=RBCS {ECO:0000256|HAMAP-Rule:MF_00860};
OS   Populus trichocarpa (Western balsam poplar) (Populus balsamifera subsp.
OS   trichocarpa).
OC   Eukaryota; Viridiplantae; Streptophyta; Embryophyta; Tracheophyta;
OC   Spermatophyta; Magnoliopsida; eudicotyledons; Gunneridae; Pentapetalae;
OC   rosids; fabids; Malpighiales; Salicaceae; Saliceae; Populus.
OX   NCBI_TaxID=3694 {ECO:0000313|EMBL:ABK95904.1};
RN   [1] {ECO:0000313|EMBL:ABK95904.1}
RP   NUCLEOTIDE SEQUENCE.
RC   TISSUE=Young and mature leaves {ECO:0000313|EMBL:ABK95904.1};
RX   PubMed=18230180; DOI=10.1186/1471-2164-9-57;
RA   Ralph S.G., Chun H.J., Cooper D., Kirkpatrick R., Kolosova N., Gunter L.,
RA   Tuskan G.A., Douglas C.J., Holt R.A., Jones S.J., Marra M.A., Bohlmann J.;
RT   "Analysis of 4,664 high-quality sequence-finished poplar full-length cDNA
RT   clones and their utility for the discovery of genes responding to insect
RT   feeding.";
RL   BMC Genomics 9:57-57(2008).
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:0000256|HAMAP-Rule:MF_00860,
CC       ECO:0000256|RuleBase:RU003627}.
CC   -!- SUBUNIT: Heterohexadecamer of 8 large and 8 small subunits.
CC       {ECO:0000256|HAMAP-Rule:MF_00860, ECO:0000256|RuleBase:RU003627}.
CC   -!- SUBCELLULAR LOCATION: Plastid, chloroplast {ECO:0000256|HAMAP-
CC       Rule:MF_00860}.
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:0000256|HAMAP-Rule:MF_00860}.
CC   -!- SIMILARITY: Belongs to the RuBisCO small chain family.
CC       {ECO:0000256|HAMAP-Rule:MF_00860, ECO:0000256|RuleBase:RU003627}.
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DR   EMBL; EF147906; ABK95904.1; -; mRNA.
DR   EMBL; EF148201; ABK96181.1; -; mRNA.
DR   AlphaFoldDB; A9PHQ1; -.
DR   SMR; A9PHQ1; -.
DR   STRING; 3694.A9PHQ1; -.
DR   Gramene; Potri.017G114600.1.v4.1; Potri.017G114600.1.v4.1; Potri.017G114600.v4.1.
DR   KEGG; pop:18099496; -.
DR   eggNOG; ENOG502QT0M; Eukaryota.
DR   HOGENOM; CLU_098114_1_0_1; -.
DR   OMA; WIPTIEF; -.
DR   OrthoDB; 561at2759; -.
DR   GO; GO:0009507; C:chloroplast; IEA:UniProtKB-SubCell.
DR   GO; GO:0016984; F:ribulose-bisphosphate carboxylase activity; IEA:UniProtKB-UniRule.
DR   GO; GO:0003723; F:RNA binding; IEA:UniProtKB-ARBA.
DR   GO; GO:0009853; P:photorespiration; IEA:UniProtKB-UniRule.
DR   GO; GO:0019253; P:reductive pentose-phosphate cycle; IEA:UniProtKB-UniRule.
DR   CDD; cd03527; RuBisCO_small; 1.
DR   FunFam; 3.30.190.10:FF:000001; Ribulose bisphosphate carboxylase small chain, chloroplastic; 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 1A, CHLOROPLASTIC-RELATED; 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   2: Evidence at transcript level;
KW   Calvin cycle {ECO:0000256|ARBA:ARBA00022567, ECO:0000256|HAMAP-
KW   Rule:MF_00860};
KW   Carbon dioxide fixation {ECO:0000256|ARBA:ARBA00023300, ECO:0000256|HAMAP-
KW   Rule:MF_00860};
KW   Chloroplast {ECO:0000256|ARBA:ARBA00022528, ECO:0000256|HAMAP-
KW   Rule:MF_00860};
KW   Photorespiration {ECO:0000256|ARBA:ARBA00023238, ECO:0000256|HAMAP-
KW   Rule:MF_00860};
KW   Photosynthesis {ECO:0000256|ARBA:ARBA00022531, ECO:0000256|HAMAP-
KW   Rule:MF_00860};
KW   Plastid {ECO:0000256|ARBA:ARBA00022640, ECO:0000256|HAMAP-Rule:MF_00860};
KW   Transit peptide {ECO:0000256|ARBA:ARBA00022946}.
FT   DOMAIN          69..178
FT                   /note="Ribulose bisphosphate carboxylase small subunit"
FT                   /evidence="ECO:0000259|SMART:SM00961"
SQ   SEQUENCE   181 AA;  20390 MW;  1DC0C95A8E5FD94D CRC64;
     MASSVISSAA VATVNRTPAQ ANMVAPFNGL KSTSAFPVTR KANNDITSIA SNGGRVQCMQ
     VWPPTGLKKF ETLSYLPDLT TEQLAQEIEY LLRNKWVPCL EFELEKGWVY REHHQSPGYY
     DGRYWTMWKL PMFGCTEASQ VLIELEEAKK AYPNSFIRII GFDNTRQVQC ISFIASKPKG
     V
//