1cnq
FRUCTOSE-1,6-BISPHOSPHATASE COMPLEXED WITH FRUCTOSE-6-PHOSPHATE AND ZINC IONSFRUCTOSE-1,6-BISPHOSPHATASE COMPLEXED WITH FRUCTOSE-6-PHOSPHATE AND ZINC IONS
Structural highlights
FunctionEvolutionary Conservation Check, as determined by ConSurfDB. You may read the explanation of the method and the full data available from ConSurf. Publication Abstract from PubMedA disordered loop (loop 52-72, residues 52-72) in crystal structures of fructose-1,6-bisphosphatase (FBPase) has been implicated in regulatory and catalytic phenomena by studies in directed mutation. A crystal structure of FBPase in a complex with three zinc cations and the products fructose 6-phosphate (F6P) and phosphate (Pi) reveals loop 52-72 for the first time in a well-defined conformation with strong electron density. Loop 52-57 interacts primarily with the active site of its own subunit. Asp68 of the loop hydrogen bonds with Arg276 and a zinc cation located at the putative potassium activation site. Leu56 and Tyr57 of the loop pack against hydrophobic residues from two separate subunits of FBPase. A mechanism of allosteric regulation of catalysis is presented, in which AMP, by binding to its allosteric pocket, displaces loop 52-72 from the active site. Furthermore, the current structure suggests that both the alpha- and beta-anomers of F6P can be substrates in the reverse reaction catalyzed by FBPase. Mechanisms of catalysis are proposed for the reverse reaction in which Asp121 serves as a catalytic base for the alpha-anomer and Glu280 serves as a catalytic base for the beta-anomer. Role of a dynamic loop in cation activation and allosteric regulation of recombinant porcine fructose-1,6-bisphosphatase.,Choe JY, Poland BW, Fromm HJ, Honzatko RB Biochemistry. 1998 Aug 18;37(33):11441-50. PMID:9708979[1] From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine. See AlsoReferences
|
| ||||||||||||||||||