UniProt functional annotation for P00880

UniProt code: P00880.

Organism: Synechococcus sp. (strain ATCC 27144 / PCC 6301 / SAUG 1402/1) (Anacystis nidulans).
Taxonomy: Bacteria; Cyanobacteria; Oscillatoriophycideae; Chroococcales; Synechococcus.
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.
Biophysicochemical properties: Kinetic parameters: KM=39 uM for ribulose 1,5-bisphosphate; KM=173 uM for CO(2); Vmax=2.5 umol/min/mg enzyme with CO(2) as substrate; Note=The CO(2)/O(2) specificity factor (tau) is 39;
Subunit: Heterohexadecamer of 8 large chains and 8 small chains; disulfide-linked. The disulfide link is formed within the large subunit homodimers.
Ptm: The disulfide bond which can form in the large chain dimeric partners within the hexadecamer appears to be associated with oxidative stress and protein turnover (By similarity). Note this disulfide bond has not been seen in these crystal structures.
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.