title: First evidence of sucrose biosynthesis by single cyanobacterial bimodular proteins.
abstract: The net synthesis of sucrose (Suc) is catalysed by the sequential action of Suc-phosphate synthase (SPS) and Suc-phosphate phosphatase (SPP). SPS and SPP from Anabaena sp. PCC 7120 (7120-SPS and 7120-SPP) define minimal catalytic units. Bidomainal SPSs, where both units are fused, occur in plants and cyanobacteria, but they display only SPS activity. Using recombinant proteins that have fused 7120-SPS and 7120-SPP, we demonstrated that they are bifunctional chimeras and that the arrangement 7120-SPS/SPP is the most efficient to catalyse the sequential reactions to yield Suc. Moreover, we present the first evidence of a bidomainal SPS present in the cyanobacterium Synechococcus elongatus PCC 7942 with both, SPS and SPP activity.
authors.affiliation: Instituto de Investigaciones en Biodiversidad y Biotecnología (INBIOTEC-CONICET) and Centro de Investigaciones Biológicas, FIBA, 7600 Mar del Plata, Argentina.
authors.forename: Giselle M A
authors.initials: GM
authors.lastname: Martínez-Noël
authors.forename: Andrea C
authors.initials: AC
authors.lastname: Cumino
authors.forename: María de los Angeles
authors.initials: Mde L
authors.lastname: Kolman
authors.forename: Graciela L
authors.initials: GL
authors.lastname: Salerno
mesh_terms: D001426:Bacterial Proteins / Q000096:biosynthesis / Q000737:chemistry*; D020134:Catalytic Domain; D003001:Cloning, Molecular; D004926:Escherichia coli; D005964:Glucosyltransferases / Q000096:biosynthesis / Q000737:chemistry* / Q000302:isolation & purification; D007700:Kinetics; D008958:Models, Molecular; D010744:Phosphoric Monoester Hydrolases / Q000096:biosynthesis / Q000737:chemistry*; D011993:Recombinant Fusion Proteins / Q000096:biosynthesis / Q000737:chemistry; D020539:Sequence Analysis, Protein; D040681:Structural Homology, Protein; D013395:Sucrose / Q000378:metabolism*; D046940:Synechococcus / Q000201:enzymology*
chemical_list: D001426:Bacterial Proteins; D011993:Recombinant Fusion Proteins; D013395:Sucrose; D005964:Glucosyltransferases; C022698:sucrose-phosphate synthase; D010744:Phosphoric Monoester Hydrolases; C022697:sucrose-phosphatase