title: Structure of the dual-function fructose-1,6/sedoheptulose-1,7-bisphosphatase from Thermosynechococcus elongatus bound with sedoheptulose-7-phosphate.
abstract: The dual-function fructose-1,6/sedoheptulose-1,7-bisphosphatase (FBP/SBPase) in cyanobacteria carries out two activities in the Calvin cycle. Structures of this enzyme from the cyanobacterium Synechocystis sp. PCC 6803 exist, but only with adenosine monophosphate (AMP) or fructose-1,6-bisphosphate and AMP bound. The mechanisms which control both selectivity between the two sugars and the structural mechanisms for redox control are still unresolved. Here, the structure of the dual-function FBP/SBPase from the thermophilic cyanobacterium Thermosynechococcus elongatus is presented with sedoheptulose-7-phosphate bound and in the absence of AMP. The structure is globally very similar to the Synechocystis sp. PCC 6803 enzyme, but highlights features of selectivity at the active site and loop ordering at the AMP-binding site. Understanding the selectivity and control of this enzyme is critical for understanding the Calvin cycle in cyanobacteria and for possible biotechnological application in plants.
authors.affiliation: Department of Life Sciences, Imperial College London, Exhibition Road, London SW7 2AZ, England.
authors.forename: Charles A R
authors.initials: CA
authors.lastname: Cotton
authors.affiliation: Department of Life Sciences, Imperial College London, Exhibition Road, London SW7 2AZ, England.
authors.forename: Burak V
authors.initials: BV
authors.lastname: Kabasakal
authors.affiliation: Department of Life Sciences, Imperial College London, Exhibition Road, London SW7 2AZ, England.
authors.forename: Nishat A
authors.initials: NA
authors.lastname: Miah
authors.affiliation: Department of Life Sciences, Imperial College London, Exhibition Road, London SW7 2AZ, England.
authors.forename: James W
authors.initials: JW
authors.lastname: Murray
mesh_terms: D000249:Adenosine Monophosphate / Q000378:metabolism; D000595:Amino Acid Sequence; D020134:Catalytic Domain; D000458:Cyanobacteria / Q000201:enzymology*; D006597:Fructose-Bisphosphatase / Q000737:chemistry*; D008969:Molecular Sequence Data; D010084:Oxidation-Reduction; D010744:Phosphoric Monoester Hydrolases / Q000737:chemistry*; D013403:Sugar Phosphates / Q000378:metabolism*; D046939:Synechocystis / Q000201:enzymology
chemical_list: D013403:Sugar Phosphates; C020495:sedoheptulose 7-phosphate; D000249:Adenosine Monophosphate; D006597:Fructose-Bisphosphatase; D010744:Phosphoric Monoester Hydrolases; C022627:sedoheptulose-bisphosphatase
keywords: Calvin cycle; cyanobacteria; fructose-1,6/sedoheptulose-1,7-bisphosphatase; photosynthesis