RUBISCO FROM GALDIERIA PARTITA
[O98949_9RHOD] 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 (By similarity).[HAMAP-Rule:MF_01338]
Publication Abstract from PubMed
Ribulose-1,5-bisphosphate carboxylase/oxygenase (Rubisco) catalyzes the reactions of carboxylation and oxygenation of ribulose-1,5-bisphosphate. These reactions require that the active site should be closed by a flexible loop (loop 6) of the large subunit. Rubisco from a red alga, Galdieria partita, has the highest specificity for carboxylation reaction among the Rubiscos hitherto reported. The crystal structure of unactivated Galdieria Rubisco has been determined at 2.6 A resolution. The electron density map reveals that a sulfate binds only to the P1 anion-binding site of the active site and the loop 6 is closed. Galdieria Rubisco has a unique hydrogen bond between the main chain oxygen of Val332 on the loop 6 and the epsilon-amino group of Gln386 of the same large subunit. This interaction is likely to be crucial to understanding for stabilizing the loop 6 in the closed state and to making a higher affinity for anionic ligands.
X-ray structure of Galdieria Rubisco complexed with one sulfate ion per active site.,Okano Y, Mizohata E, Xie Y, Matsumura H, Sugawara H, Inoue T, Yokota A, Kai Y FEBS Lett. 2002 Sep 11;527(1-3):33-6. PMID:12220629
From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine.