UniProt functional annotation for P00875

UniProt code: P00875.

Organism: Spinacia oleracea (Spinach).
Taxonomy: Eukaryota; Viridiplantae; Streptophyta; Embryophyta; Tracheophyta; Spermatophyta; Magnoliophyta; eudicotyledons; Gunneridae; Pentapetalae; Caryophyllales; Amaranthaceae; Chenopodioideae; Anserineae; Spinacia.
 
Function: RuBisCO catalyzes two reactions: the carboxylation of D- ribulose 1,5-bisphosphate, the primary event in carbon dioxide fixation, as well as the oxidative fragmentation of the pentose substrate in the photorespiration process. Both reactions occur simultaneously and in competition at the same active site.
 
Catalytic activity: 2 3-phospho-D-glycerate + 2 H(+) = D-ribulose 1,5-bisphosphate + CO(2) + H(2)O.
Catalytic activity: 3-phospho-D-glycerate + 2-phosphoglycolate = D-ribulose 1,5-bisphosphate + O(2).
Cofactor: Binds 1 magnesium ion per subunit.
Subunit: Heterohexadecamer of 8 large chains and 8 small chains; disulfide-linked. The disulfide link is formed within the large subunit homodimers. {ECO:0000269|PubMed:8955130}.
Subcellular location: Plastid, chloroplast.
Ptm: The disulfide bond which can form between Cys-247 in the large chain dimeric partners within the hexadecamer appears to be associated with oxidative stress and protein turnover (By similarity). The disulfide bonds reported in 1RBO may be the result of oxidation during crystallization. {ECO:0000250}.
Miscellaneous: The basic functional RuBisCO is composed of a large chain homodimer in a "head-to-tail" conformation. In form I RuBisCO this homodimer is arranged in a barrel-like tetramer with the small subunits forming a tetrameric "cap" on each end of the "barrel".
Similarity: Belongs to the RuBisCO large chain family. Type I subfamily. {ECO:0000305}.

Annotations taken from UniProtKB at the EBI.