title: Purification and properties of the F sex factor TraD protein, an inner membrane conjugal transfer protein.
abstract: Using a traD overexpression plasmid, we purified the F sex factor TraD protein in milligram quantities. The purified protein has an apparent molecular weight of 82,000 and an amino acid composition rich in acidic residues. Using specific antibodies, TraD was localized to the inner membrane of F+ cells under conditions where it is produced in physiologically normal amounts. Furthermore, the protein was soluble only in the presence of detergents, but there is evidence that the carboxyl terminus is water-soluble. The purified protein shows pH-sensitive binding to DNA cellulose columns.
authors.affiliation: Department of Biological Sciences, Carnegie Mellon University, Pittsburgh, Pennsylvania 15213.
authors.forename: M M
authors.initials: MM
authors.lastname: Panicker
authors.forename: E G
authors.initials: EG
authors.lastname: Minkley
mesh_terms: D000596:Amino Acids / Q000032:analysis; D001426:Bacterial Proteins / Q000737:chemistry / Q000302:isolation & purification / Q000378:metabolism*; D002846:Chromatography, Affinity; D003001:Cloning, Molecular; D004268:DNA-Binding Proteins / Q000737:chemistry / Q000302:isolation & purification / Q000378:metabolism; D004591:Electrophoresis, Polyacrylamide Gel; D004926:Escherichia coli / Q000378:metabolism*; D029968:Escherichia coli Proteins; D005144:F Factor; D007425:Intracellular Membranes / Q000378:metabolism*; D007525:Isoelectric Focusing; D008565:Membrane Proteins / Q000737:chemistry / Q000302:isolation & purification / Q000378:metabolism; D008970:Molecular Weight; D010957:Plasmids
chemical_list: D000596:Amino Acids; D001426:Bacterial Proteins; D004268:DNA-Binding Proteins; D029968:Escherichia coli Proteins; D008565:Membrane Proteins; C064957:traD protein, E coli