PDBsum entry: 1d9q

Hydrolase

PDB id: 1d9q

Contents

Protein chains

323 a.a. *

Waters ×334

* Residue conservation analysis

PDB id:

1d9q

Name:

Hydrolase

Title:

Oxidized pea fructose-1,6-bisphosphatase form 1

Structure:

Fructose-1,6-bisphosphatase. Chain: a, b, c, d. Synonym: fbpase,d-fructose-1,6-bisphosphate 1- phosphohydrolase. Engineered: yes

Source:

Pisum sativum. Pea. Organism_taxid: 3888. Organelle: chloroplast. Expressed in: escherichia coli. Expression_system_taxid: 562

Biol. unit:

Tetramer (from PQS)

Resolution:

2.40Å R-factor: 0.186 R-free: 0.236

Authors:

M.Chiadmi,A.Navaza,M.Miginiac-Maslow,J.-P.Jacquot,J.Cherfils

Key ref:

M.Chiadmi et al. (1999). Redox signalling in the chloroplast: structure of oxidized pea fructose-1,6-bisphosphate phosphatase. EMBO J, 18, 6809-6815. PubMed id: 10581254 DOI: 10.1093/emboj/18.23.6809

Date:

29-Oct-99 Release date: 03-Dec-99

Protein chains

P46275  (F16P1_PEA) -  Fructose-1,6-bisphosphatase, chloroplastic

Seq: 407 a.a.

Struc: 323 a.a.*

* PDB and UniProt seqs differ at 3 residue positions (black crosses)

Enzyme reactions

• Enzyme class: E.C.3.1.3.11 - Fructose-bisphosphatase.
• Pathway: Pentose Phosphate Pathway (later stages)
• Reaction: D-fructose 1,6-bisphosphate + H₂O = D-fructose 6-phosphate + phosphate

Molecule diagrams generated from .mol files obtained from the KEGG ftp site

 Gene Ontology (GO) functional annotation 

• Biological process: carbohydrate metabolic process (1 term)
• Biochemical function: phosphoric ester hydrolase activity (1 term)

reference

DOI no: 10.1093/emboj/18.23.6809

EMBO J 18:6809-6815 (1999)

PubMed id: 10581254

Redox signalling in the chloroplast: structure of oxidized pea fructose-1,6-bisphosphate phosphatase.

M.Chiadmi, A.Navaza, M.Miginiac-Maslow, J.P.Jacquot, J.Cherfils.

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.

Selected figure(s)

Figure 2.
Figure 2 Comparison of oxidized pea FBPase to pig kidney and spinach FBPases. (A) Oxidized form I pea FBPase. (B) Chloroplastic spinach FBPase (PDB entry code 1SPI) (Villeret et al., 1995). (C) R form gluconeogenic pig kidney FBPase in complex with F6P, P[i] and Zn2+ (PDB entry code 1CNQ) (Choe et al., 1998). (D) Close-up view of the cation binding site with pig kidney FBPase shown in blue, cations in red and oxidized pea FBPase in yellow. Orientation and colour coding in (A), (B) and (C) are as in Figure 1A. The location of the active site in pea and spinach FBPases is indicated by a model of F6P, P[i] and Zn2+ shown as dashed lines. The 70's loop in pig kidney FBPase is in blue. The corresponding loop is disordered in pea and spinach FBPases. The loop in pig kidney FBPase that corresponds to the chloroplastic insertion is in red. The binding site for AMP in pig kidney FBPase is indicated by one of its ligands, Lys112. The close-up view in (D) shows that the interaction of the 70's loop and the loop between strands 1 and 2 with the cations in pig FBPase, is prevented by the inwards movement of strands 1and 2 in oxidized pea FBPase. This movement places Val109 near the location of the cation binding site and removes Glu105, which corresponds to Glu97 in pig kidney FBPase, from the active site.

Figure 3.
Figure 3 The insertion in wild-type form I (dark grey) and in the Cys173Ser mutant (light grey). Residues 155 -168 are weakly defined in the electron density of form I (dashed lines) and cannot be traced in the C173S mutant.

The above figures are reprinted from an Open Access publication published by Macmillan Publishers Ltd: EMBO J (1999, 18, 6809-6815) copyright 1999.

Figures were selected by an automated process.