1YYZ
R-State AMP Complex Reveals Initial Steps of the Quaternary Transition of Fructose-1,6-bisphosphatase
Summary for 1YYZ
| Entry DOI | 10.2210/pdb1yyz/pdb |
| Related | 1CNQ 1FJ6 1NUY 1YXI 1YZ0 |
| Descriptor | Fructose-1,6-bisphosphatase, 6-O-phosphono-beta-D-fructofuranose, PHOSPHATE ION, ... (6 entities in total) |
| Functional Keywords | allostearic enzymes, intermediate states, fructose-1, 6-bisphosphatase, fbpase, glycolysis, gluconeogenesis, hydrolase |
| Biological source | Sus scrofa (pig) |
| Total number of polymer chains | 1 |
| Total formula weight | 37484.23 |
| Authors | Iancu, C.V.,Mukund, S.,Fromm, H.J.,Honzatko, R.B. (deposition date: 2005-02-25, release date: 2005-03-15, Last modification date: 2023-08-23) |
| Primary citation | Iancu, C.V.,Mukund, S.,Fromm, H.J.,Honzatko, R.B. R-state AMP complex reveals initial steps of the quaternary transition of fructose-1,6-bisphosphatase. J.Biol.Chem., 280:19737-19745, 2005 Cited by PubMed Abstract: AMP transforms fructose-1,6-bisphosphatase from its active R-state to its inactive T-state; however, the mechanism of that transformation is poorly understood. The mutation of Ala(54) to leucine destabilizes the T-state of fructose-1,6-bisphosphatase. The mutant enzyme retains wild-type levels of activity, but the concentration of AMP that causes 50% inhibition increases 50-fold. In the absence of AMP, the Leu(54) enzyme adopts an R-state conformation nearly identical to that of the wild-type enzyme. The mutant enzyme, however, grows in two crystal forms in the presence of saturating AMP. In one form, the AMP-bound tetramer is in a T-like conformation, whereas in the other form, the AMP-bound tetramer is in a R-like conformation. The latter reveals conformational changes in two helices due to the binding of AMP. Helix H1 moves toward the center of the tetramer and displaces Ile(10) from a hydrophobic pocket. The displacement of Ile(10) exposes a hydrophobic surface critical to interactions that stabilize the T-state. Helix H2 moves away from the center of the tetramer, breaking hydrogen bonds with a buried loop (residues 187-195) in an adjacent subunit. The same hydrogen bonds reform but only after the quaternary transition to the T-state. Proposed here is a model that accounts for the quaternary transition and cooperativity in the inhibition of catalysis by AMP. PubMed: 15767255DOI: 10.1074/jbc.M501011200 PDB entries with the same primary citation |
| Experimental method | X-RAY DIFFRACTION (1.85 Å) |
Structure validation
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