1D9Q

OXIDIZED PEA FRUCTOSE-1,6-BISPHOSPHATASE FORM 1

Summary for 1D9Q

• Entry DOI: 10.2210/pdb1d9q/pdb
• Related: 1DBZ 1DCU 1LUZ
• Descriptor: FRUCTOSE-1,6-BISPHOSPHATASE (2 entities in total)
• Functional Keywords: chloroplast, photosynthesis, redox regulation, thioredoxin, allostery, disulfide bridge, calvin cycle, hydrolase
• Biological source: Pisum sativum (pea)
• Cellular location: Plastid, chloroplast stroma: P46275
• Total number of polymer chains: 4
• Total formula weight: 156968.11

Authors

Chiadmi, M.,Navaza, A.,Miginiac-Maslow, M.,Jacquot, J.-P.,Cherfils, J. (deposition date: 1999-10-29, release date: 1999-12-03, Last modification date: 2023-08-09)

Primary citation

Chiadmi, M.,Navaza, A.,Miginiac-Maslow, M.,Jacquot, J.P.,Cherfils, J.
Redox signalling in the chloroplast: structure of oxidized pea fructose-1,6-bisphosphate phosphatase.
EMBO J., 18:6809-6815, 1999

PubMed Abstract: Sunlight provides the energy source for the assimilation of carbon dioxide by photosynthesis, but it also provides regulatory signals that switch on specific sets of enzymes involved in the alternation of light and dark metabolisms in chloroplasts. Capture of photons by chlorophyll pigments triggers redox cascades that ultimately activate target enzymes via the reduction of regulatory disulfide bridges by thioredoxins. Here we report the structure of the oxidized, low-activity form of chloroplastic fructose-1, 6-bisphosphate phosphatase (FBPase), one of the four enzymes of the Calvin cycle whose activity is redox-regulated by light. The regulation is of allosteric nature, with a disulfide bridge promoting the disruption of the catalytic site across a distance of 20 A. Unexpectedly, regulation of plant FBPases by thiol-disulfide interchange differs in every respect from the regulation of mammalian gluconeogenic FBPases by AMP. We also report a second crystal form of oxidized FBPase whose tetrameric structure departs markedly from D(2) symmetry, a rare event in oligomeric structures, and the structure of a constitutively active mutant that is unable to form the regulatory disulfide bridge. Altogether, these structures provide a structural basis for redox regulation in the chloroplast.

PubMed: 10581254
DOI: 10.1093/emboj/18.23.6809

Experimental method

X-RAY DIFFRACTION (2.4 Å)