ID   RBS2_MESCR              Reviewed;         180 AA.
AC   Q04450;
DT   01-OCT-1994, integrated into UniProtKB/Swiss-Prot.
DT   01-OCT-1994, sequence version 1.
DT   25-MAY-2022, entry version 92.
DE   RecName: Full=Ribulose bisphosphate carboxylase small subunit, chloroplastic 2 {ECO:0000255|HAMAP-Rule:MF_00860};
DE            Short=RuBisCO small subunit 2 {ECO:0000255|HAMAP-Rule:MF_00860};
DE   Flags: Precursor;
GN   Name=RBCS2 {ECO:0000255|HAMAP-Rule:MF_00860};
GN   Synonyms=RBCS-2 {ECO:0000303|PubMed:8316216};
OS   Mesembryanthemum crystallinum (Common ice plant) (Cryophytum crystallinum).
OC   Eukaryota; Viridiplantae; Streptophyta; Embryophyta; Tracheophyta;
OC   Spermatophyta; Magnoliopsida; eudicotyledons; Gunneridae; Pentapetalae;
OC   Caryophyllales; Aizoaceae; Mesembryanthemum;
OC   Mesembryanthemum subgen. Cryophytum.
OX   NCBI_TaxID=3544;
RN   [1]
RP   NUCLEOTIDE SEQUENCE, AND INDUCTION.
RX   PubMed=8316216; DOI=10.1007/bf00276944;
RA   Derocher E.J., Quigley F., Mache R., Bohnert H.J.;
RT   "The six genes of the Rubisco small subunit multigene family from
RT   Mesembryanthemum crystallinum, a facultative CAM plant.";
RL   Mol. Gen. Genet. 239:450-462(1993).
RN   [2]
RP   NUCLEOTIDE SEQUENCE.
RX   PubMed=16668083; DOI=10.1104/pp.95.3.976;
RA   Derocher E.J., Michalowski C.B., Bohnert H.J.;
RT   "cDNA sequences for transcripts of the ribulose-1,5-bisphosphate
RT   carboxylase/oxygenase small subunit gene family of Mesembryanthemum
RT   crystallinum.";
RL   Plant Physiol. 95:976-978(1991).
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_00860}.
CC   -!- SUBUNIT: Heterohexadecamer of 8 large and 8 small subunits.
CC       {ECO:0000255|HAMAP-Rule:MF_00860}.
CC   -!- SUBCELLULAR LOCATION: Plastid, chloroplast {ECO:0000255|HAMAP-
CC       Rule:MF_00860}.
CC   -!- INDUCTION: The least expressed of the 6 small subunit genes.
CC       {ECO:0000269|PubMed:8316216}.
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}.
CC   -!- SIMILARITY: Belongs to the RuBisCO small chain family.
CC       {ECO:0000255|HAMAP-Rule:MF_00860}.
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DR   EMBL; L10214; AAA03694.1; -; Unassigned_DNA.
DR   EMBL; M38316; AAA33036.1; -; mRNA.
DR   PIR; S35246; S35246.
DR   AlphaFoldDB; Q04450; -.
DR   SMR; Q04450; -.
DR   GO; GO:0009507; C:chloroplast; 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; IPR024680; RuBisCO_ssu_N.
DR   InterPro; IPR036385; RuBisCO_ssu_sf.
DR   PANTHER; PTHR31262; PTHR31262; 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; SSF55239; 1.
PE   2: Evidence at transcript level;
KW   Calvin cycle; Carbon dioxide fixation; Chloroplast; Photorespiration;
KW   Photosynthesis; Plastid; Transit peptide.
FT   TRANSIT         1..54
FT                   /note="Chloroplast"
FT                   /evidence="ECO:0000255|HAMAP-Rule:MF_00860"
FT   CHAIN           55..180
FT                   /note="Ribulose bisphosphate carboxylase small subunit,
FT                   chloroplastic 2"
FT                   /evidence="ECO:0000255|HAMAP-Rule:MF_00860"
FT                   /id="PRO_0000031528"
FT   CONFLICT        154
FT                   /note="T -> I (in Ref. 2; AAA33036)"
FT                   /evidence="ECO:0000305"
SQ   SEQUENCE   180 AA;  20084 MW;  6977DC72C89940F3 CRC64;
     MASMMSNAAV VGRTTPAQAS MVAPFTGLKS VSAFPVTKKS NDITSIASNG GRVQCMQVWP
     PLGKKKFETL SYLPPLSEES LMKEVQYLLN NGWVPCLEFE PTHGFVYREH GNTPGYYDGR
     YWTMWKLPMF GCTDPSQVVA ELEEAKKAYP EAFTRIIGFD NVRQVQCISF IAYKPASYDA