title: SocA is a novel periplasmic binding protein for fructosyl amino acid.
abstract: Bacterial periplasmic proteins (bPBPs) undergo drastic conformational changes upon binding substrate, making them appealing as novel molecular recognition tools for biosensing. A putative bPBP-encoding gene, socA, belongs to the soc operon responsible for santhopine (fructosyl glutamine, FQ) catabolism of Agrobacterium tumefaciens. The socA gene was isolated and expressed in Escherichia coli as a soluble 28.8kDa periplasmic protein to investigate its properties as a potential bPBP for fructosyl amino acid (FA). The autofluorescence of SocA was used to monitor the protein's conformational change resulting from substrate binding. The fluorescence intensity changed upon binding FQ in a concentration dependent manner with a calculated K(d) of 2.1muM, but was unaffected by the presence of sugars or amino acid. Our results demonstrate that SocA is a novel FA bPBP that can be utilized as a novel molecular recognition element for the monitoring of FA.
authors.affiliation: Department of Biotechnology, Tokyo University of Agriculture and Technology, Koganei, Japan.
authors.forename: Akane
authors.initials: A
authors.lastname: Sakaguchi
authors.forename: Stefano
authors.initials: S
authors.lastname: Ferri
authors.forename: Koji
authors.initials: K
authors.lastname: Sode
mesh_terms: D016960:Agrobacterium tumefaciens / Q000378:metabolism*; D000595:Amino Acid Sequence; D000596:Amino Acids / Q000378:metabolism*; D001426:Bacterial Proteins / Q000737:chemistry* / Q000302:isolation & purification / Q000378:metabolism; D003001:Cloning, Molecular; D004926:Escherichia coli / Q000235:genetics / Q000378:metabolism; D005453:Fluorescence; D005632:Fructose / Q000378:metabolism*; D008969:Molecular Sequence Data; D033902:Periplasmic Binding Proteins / Q000737:chemistry* / Q000302:isolation & purification / Q000378:metabolism; D011485:Protein Binding; D011994:Recombinant Proteins / Q000737:chemistry / Q000302:isolation & purification / Q000378:metabolism; D013379:Substrate Specificity
chemical_list: D000596:Amino Acids; D001426:Bacterial Proteins; D033902:Periplasmic Binding Proteins; D011994:Recombinant Proteins; D005632:Fructose