title: Topological analysis of the lysine-specific permease of Escherichia coli.
abstract: Escherichia coli accumulates lysine via two systems, one specific for lysine (LysP) and a second inhibited by arginine or ornithine (LAO). The lysP gene encodes a polypeptide of 489 residues. A topological analysis of the LysP protein was performed using gene fusions. Random in-frame fusions of the lysP gene with the lacZ or blaM genes were generated. Site-directed mutagenesis was also used to generate additional blaM fusions at specific locations in the lysP gene. Two methods were used to alleviate the problem of lethal expression of some lysP::blaM fusions. First, ternary fusions were constructed in which the arsD gene was fused at the 5' end of the lysP gene and the blaM gene fused at specific sites within the lysP gene. In these plasmids lysP expression was controlled by the ars promoter. Secondly, an E. coli strain with a pcnB mutation was used with some fusions to maintain the plasmids at a reduced copy number. From analysis of 30 gene fusions, a topological model of the LysP protein is proposed in which the protein has 12 membrane-spanning regions, with the N- and C-terminal in the cytosol.
authors.forename: Jeri
authors.initials: J
authors.lastname: Ellis
authors.forename: Arthur
authors.initials: A
authors.lastname: Carlin
authors.forename: Chris
authors.initials: C
authors.lastname: Steffes
authors.forename: Jianhua
authors.initials: J
authors.lastname: Wu
authors.forename: Jiyang
authors.initials: J
authors.lastname: Liu
authors.forename: Barry P
authors.initials: BP
authors.lastname: Rosen
mesh_terms: D026923:Amino Acid Transport Systems, Basic; D001426:Bacterial Proteins / Q000378:metabolism; D001483:Base Sequence; D002462:Cell Membrane / Q000737:chemistry; D004926:Escherichia coli / Q000235:genetics / Q000378:metabolism*; D029968:Escherichia coli Proteins; D026901:Membrane Transport Proteins / Q000737:chemistry* / Q000235:genetics; D008956:Models, Chemical; D008969:Molecular Sequence Data; D016297:Mutagenesis, Site-Directed; D011062:Polynucleotide Adenylyltransferase; D017433:Protein Structure, Secondary; D017434:Protein Structure, Tertiary; D011993:Recombinant Fusion Proteins / Q000378:metabolism; D029701:Saccharomyces cerevisiae Proteins; D013329:Structure-Activity Relationship; D015534:Trans-Activators / Q000235:genetics; D001616:beta-Galactosidase / Q000235:genetics / Q000378:metabolism; D001618:beta-Lactamases / Q000235:genetics / Q000378:metabolism
chemical_list: D026923:Amino Acid Transport Systems, Basic; D001426:Bacterial Proteins; D029968:Escherichia coli Proteins; C430023:LYP1 protein, S cerevisiae; D026901:Membrane Transport Proteins; D011993:Recombinant Fusion Proteins; D029701:Saccharomyces cerevisiae Proteins; D015534:Trans-Activators; C430024:lysP protein, E coli; D011062:Polynucleotide Adenylyltransferase; C063643:pcnB protein, E coli; D001616:beta-Galactosidase; D001618:beta-Lactamases