1rsc
From Proteopedia
STRUCTURE OF AN EFFECTOR INDUCED INACTIVATED STATE OF RIBULOSE BISPHOSPHATE CARBOXYLASE(SLASH)OXYGENASE: THE BINARY COMPLEX BETWEEN ENZYME AND XYLULOSE BISPHOSPHATE
Structural highlights
Function[RBL_SYNP6] 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.[HAMAP-Rule:MF_01338] [RBS_SYNP6] 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. Both reactions occur simultaneously and in competition at the same active site. Evolutionary Conservation Check, as determined by ConSurfDB. You may read the explanation of the method and the full data available from ConSurf. Publication Abstract from PubMedBACKGROUND: Ribulose 1,5-bisphosphate carboxylase/oxygenase (rubisco) catalyzes the addition of CO2 to ribulose 1,5-bisphosphate in all photosynthetic organisms. During catalysis, the bisphosphate is depleted by reactions other than carboxylation and some of the products are potent inhibitors of rubisco. We have used one of these, xylulose 1,5-bisphosphate as an analogue of the natural substrate and co-crystallized it with the enzyme. RESULTS: We have solved the crystal structure of Synechococcus rubisco with bound xylulose 1,5-bisphosphate to 2.3 A and compared it with the previously solved 2'-carboxylarabinitol 1,5-bisphosphate (2CABP) enzyme quaternary complex. Unlike 2CABP, xylulose 1,5-bisphosphate forms a binary complex with no activating CO2 or essential metal present. Five flexible elements that restrict access to the active site in the 2CABP complex also close off the active site in the xylulose 1,5-bisphosphate complex, stabilized by interactions with the hydrated form of the analogue. CONCLUSIONS: Xylulose 1,5-bisphosphate induces closure of critical loops of the protein without essential cofactors resident at the active site. In the case of rubisco in one species, catalysis is completely inhibited. Structure of an effector-induced inactivated state of ribulose 1,5-bisphosphate carboxylase/oxygenase: the binary complex between enzyme and xylulose 1,5-bisphosphate.,Newman J, Gutteridge S Structure. 1994 Jun 15;2(6):495-502. PMID:7922027[1] From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine. See AlsoReferences
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