UniProt functional annotation for O58677

UniProt code: O58677.

Organism: Pyrococcus horikoshii (strain ATCC 700860 / DSM 12428 / JCM 9974 / NBRC 100139 / OT-3).
Taxonomy: Archaea; Euryarchaeota; Thermococci; Thermococcales; Thermococcaceae; Pyrococcus.
Function: Catalyzes the addition of molecular CO(2) and H(2)O to ribulose 1,5-bisphosphate (RuBP), generating two molecules of 3- phosphoglycerate (3-PGA). Functions in an archaeal AMP degradation pathway, together with AMP phosphorylase and R15P isomerase. {ECO:0000255|HAMAP-Rule:MF_01133}.
Catalytic activity: 2 3-phospho-D-glycerate + 2 H(+) = D-ribulose 1,5-bisphosphate + CO(2) + H(2)O. {ECO:0000255|HAMAP- Rule:MF_01133}.
Catalytic activity: 3-phospho-D-glycerate + 2-phosphoglycolate = D-ribulose 1,5-bisphosphate + O(2). {ECO:0000255|HAMAP- Rule:MF_01133}.
Cofactor: Name=Mg(2+); Xref=ChEBI:CHEBI:18420; Evidence={ECO:0000255|HAMAP-Rule:MF_01133}; Note=Binds 1 Mg(2+) ion per subunit. {ECO:0000255|HAMAP- Rule:MF_01133};
Subunit: Homodimer or homodecamer. In contrast to form I RuBisCO, the form III RuBisCO is composed solely of large subunits. {ECO:0000255|HAMAP-Rule:MF_01133}.
Miscellaneous: Because the Archaea possessing a type III RuBisCO are all anaerobic, it is most likely that only the carboxylase activity of RuBisCO, and not the competitive oxygenase activity (by which RuBP reacts with O(2) to form one molecule of 3- phosphoglycerate and one molecule of 2-phosphoglycolate), is biologically relevant in these strains. {ECO:0000255|HAMAP- Rule:MF_01133}.
Similarity: Belongs to the RuBisCO large chain family. Type III subfamily. {ECO:0000255|HAMAP-Rule:MF_01133}.

Annotations taken from UniProtKB at the EBI.