1S2O

X-Ray structure of the sucrose-phosphatase (SPP) from Synechocystis sp. PCC6803 at 1.40 A resolution

Summary for 1S2O

• Entry DOI: 10.2210/pdb1s2o/pdb
• Descriptor: sucrose-phosphatase, MAGNESIUM ION (3 entities in total)
• Functional Keywords: phosphohydrolase, had superfamily, sucrose, cyanobacteria, hydrolase
• Biological source: Synechocystis sp.
• Total number of polymer chains: 1
• Total formula weight: 27814.17

Authors

Fieulaine, S.,Lunn, J.E.,Borel, F.,Ferrer, J.L. (deposition date: 2004-01-09, release date: 2005-02-22, Last modification date: 2024-02-14)

Primary citation

Fieulaine, S.,Lunn, J.E.,Borel, F.,Ferrer, J.L.
The structure of a cyanobacterial sucrose-phosphatase reveals the sugar tongs that release free sucrose in the cell.
Plant Cell, 17:2049-2058, 2005

PubMed Abstract: Sucrose-phosphatase (SPP) catalyzes the final step in the pathway of sucrose biosynthesis in both plants and cyanobacteria, and the SPPs from these two groups of organisms are closely related. We have crystallized the enzyme from the cyanobacterium Synechocystis sp PCC 6803 and determined its crystal structure alone and in complex with various ligands. The protein consists of a core domain containing the catalytic site and a smaller cap domain that contains a glucose binding site. Two flexible hinge loops link the two domains, forming a structure that resembles a pair of sugar tongs. The glucose binding site plays a major role in determining the enzyme's remarkable substrate specificity and is also important for its inhibition by sucrose and glucose. It is proposed that the catalytic reaction is initiated by nucleophilic attack on the substrate by Asp9 and involves formation of a covalent phospho-Asp9-enzyme intermediate. From modeling based on the SPP structure, we predict that the noncatalytic SPP-like domain of the Synechocystis sucrose-phosphate synthase could bind sucrose-6(F)-phosphate and propose that this domain might be involved in metabolite channeling between the last two enzymes in the pathway of sucrose synthesis.

PubMed: 15937230
DOI: 10.1105/tpc.105.031229

Experimental method

X-RAY DIFFRACTION (1.4 Å)