ID   RBS_THANO               Reviewed;         139 AA.
AC   O98948;
DT   01-JUN-2001, integrated into UniProtKB/Swiss-Prot.
DT   01-MAY-1999, sequence version 1.
DT   25-MAY-2022, entry version 80.
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=rbcS {ECO:0000255|HAMAP-Rule:MF_00859};
OS   Thalassiosira nordenskioeldii (Marine diatom).
OG   Plastid; Chloroplast.
OC   Eukaryota; Sar; Stramenopiles; Ochrophyta; Bacillariophyta;
OC   Coscinodiscophyceae; Thalassiosirophycidae; Thalassiosirales;
OC   Thalassiosiraceae; Thalassiosira.
OX   NCBI_TaxID=83372;
RN   [1]
RP   NUCLEOTIDE SEQUENCE [GENOMIC DNA].
RA   Tomizawa K.;
RT   "Structure and function study of ribulose-1,5-bisphosphate
RT   carboxylase/oxygenase of the marine diatom, Thalassiosira
RT   nordenskioeldii.";
RL   Submitted (SEP-1998) to the EMBL/GenBank/DDBJ databases.
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.
CC       {ECO:0000255|HAMAP-Rule:MF_00859}.
CC   -!- SUBCELLULAR LOCATION: Plastid, chloroplast {ECO:0000255|HAMAP-
CC       Rule:MF_00859}.
CC   -!- MISCELLANEOUS: In this alga, in contrast to plants, the small subunit
CC       is encoded in the chloroplast.
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; AB018007; BAA75795.1; -; Genomic_DNA.
DR   AlphaFoldDB; O98948; -.
DR   SMR; O98948; -.
DR   GO; GO:0009507; C:chloroplast; IEA:UniProtKB-SubCell.
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   3: Inferred from homology;
KW   Calvin cycle; Carbon dioxide fixation; Chloroplast; Photorespiration;
KW   Photosynthesis; Plastid.
FT   CHAIN           1..139
FT                   /note="Ribulose bisphosphate carboxylase small subunit"
FT                   /id="PRO_0000198606"
SQ   SEQUENCE   139 AA;  15897 MW;  7112892F351D10A7 CRC64;
     MRLTQGCFSF LPDLTDTQIE KQVAYAMNKG WAMNVEWTDD PHPRNNYWEL WGLPLFDIKD
     PATVMFELNE ARKSCASGYI RINAFDASYG VESCVMSFIT NRPATEPGFY LDRTEGPGRQ
     VIYSIKSYSV QANPEGSRY