title: Glucosylglycerate biosynthesis in the deepest lineage of the Bacteria: characterization of the thermophilic proteins GpgS and GpgP from Persephonella marina.
abstract: The pathway for the synthesis of glucosylglycerate (GG) in the thermophilic bacterium Persephonella marina is proposed based on the activities of recombinant glucosyl-3-phosphoglycerate (GPG) synthase (GpgS) and glucosyl-3-phosphoglycerate phosphatase (GpgP). The sequences of gpgS and gpgP from the cold-adapted bacterium Methanococcoides burtonii were used to identify the homologues in the genome of P. marina, which were separately cloned and overexpressed as His-tagged proteins in Escherichia coli. The recombinant GpgS protein of P. marina, unlike the homologue from M. burtonii, which was specific for GDP-glucose, catalyzed the synthesis of GPG from UDP-glucose, GDP-glucose, ADP-glucose, and TDP-glucose (in order of decreasing efficiency) and from d-3-phosphoglycerate, with maximal activity at 90 degrees C. The recombinant GpgP protein, like the M. burtonii homologue, dephosphorylated GPG and mannosyl-3-phosphoglycerate (MPG) to GG and mannosylglycerate, respectively, yet at high temperatures the hydrolysis of GPG was more efficient than that of MPG. Gel filtration indicates that GpgS is a dimeric protein, while GpgP is monomeric. This is the first characterization of genes and enzymes for the synthesis of GG in a thermophile.
authors.affiliation: Departamento de Bioquímica, Universidade de Coimbra, 3001-401 Coimbra, Portugal.
authors.forename: Joana
authors.initials: J
authors.lastname: Costa
authors.forename: Nuno
authors.initials: N
authors.lastname: Empadinhas
authors.forename: Milton S
authors.initials: MS
authors.lastname: da Costa
mesh_terms: D001419:Bacteria / Q000378:metabolism*; D001426:Bacterial Proteins / Q000235:genetics / Q000378:metabolism*; D001483:Base Sequence; D002384:Catalysis; D005960:Glucosides / Q000096:biosynthesis*; D005988:Glyceric Acids / Q000378:metabolism*; D006156:Guanosine Diphosphate Sugars / Q000378:metabolism*; D008969:Molecular Sequence Data; D010744:Phosphoric Monoester Hydrolases / Q000235:genetics / Q000378:metabolism; D017853:Phosphotransferases (Alcohol Group Acceptor) / Q000502:physiology; D010802:Phylogeny
chemical_list: D001426:Bacterial Proteins; D005960:Glucosides; D005988:Glyceric Acids; D006156:Guanosine Diphosphate Sugars; C100085:guanosine diphosphate glucose; C005156:3-phosphoglycerate; D017853:Phosphotransferases (Alcohol Group Acceptor); C441640:mannosyl-3-phosphoglycerate phosphatase; D010744:Phosphoric Monoester Hydrolases; C022364:phosphoglycerate phosphatase