title: Mutations that alter the equilibrium between open and closed conformations of Escherichia coli maltose-binding protein impede its ability to enhance the solubility of passenger proteins.
abstract: Certain highly soluble proteins, such as Escherichia coli maltose-binding protein (MBP), have the ability to enhance the solubility of their fusion partners, making them attractive vehicles for the production of recombinant proteins, yet the mechanism of solubility enhancement remains poorly understood. Here, we report that the solubility-enhancing properties of MBP are dramatically affected by amino acid substitutions that alter the equilibrium between its "open" and "closed" conformations. Our findings indicate that the solubility-enhancing activity of MBP is mediated by its open conformation and point to a likely role for the ligand-binding cleft in the mechanism of solubility enhancement.
authors.affiliation: Macromolecular Crystallography Laboratory, Center for Cancer Research, National Cancer Institute at Frederick, P.O. Box B, Frederick, MD 21702-1201, USA.
authors.forename: Sreedevi
authors.initials: S
authors.lastname: Nallamsetty
authors.forename: David S
authors.initials: DS
authors.lastname: Waugh
mesh_terms: D004926:Escherichia coli / Q000235:genetics / Q000378:metabolism*; D029968:Escherichia coli Proteins / Q000737:chemistry* / Q000235:genetics / Q000378:metabolism*; D007700:Kinetics; D016297:Mutagenesis, Site-Directed; D033902:Periplasmic Binding Proteins / Q000737:chemistry* / Q000235:genetics / Q000378:metabolism*; D011487:Protein Conformation; D021381:Protein Transport / Q000502:physiology*; D011994:Recombinant Proteins / Q000378:metabolism*; D012995:Solubility; D013329:Structure-Activity Relationship
chemical_list: D029968:Escherichia coli Proteins; C461619:MalE protein, E coli; D033902:Periplasmic Binding Proteins; D011994:Recombinant Proteins