UniProt functional annotation for P00876

UniProt code: P00876.

Organism: Nicotiana tabacum (Common tobacco).
Taxonomy: Eukaryota; Viridiplantae; Streptophyta; Embryophyta; Tracheophyta; Spermatophyta; Magnoliophyta; eudicotyledons; Gunneridae; Pentapetalae; asterids; lamiids; Solanales; Solanaceae; Nicotianoideae; Nicotianeae; Nicotiana.
 
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.
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 3RUB and 4RUB may be the result of oxidation during crystallization.
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.

Annotations taken from UniProtKB at the EBI.