title: Mutational analysis of slyD, an Escherichia coli gene encoding a protein of the FKBP immunophilin family.
abstract: slyD encodes a 196 amino acid polypeptide that is a member of the FKBP family of cis-trans peptidyl-prolyl isomerases (PPlases). slyD mutations affect plaque formation by the phage phiX174 by blocking the action of the phage lysis protein E. Here we describe the selection of a set of spontaneous slyD mutations conferring resistance to the expression of gene E from a plasmid. These mutations occur disproportionately in residues of SlyD that, based on the structure of the prototype mammalian FKBP12, make ligand contacts with immunosuppressing drug molecules or are conserved in other FKBP proteins. A wide variation in the plating efficiency of phiX174 on these E(R) strains is observed, relative to the parental, indicating that these alleles differ widely in residual SlyD activity. Moreover, it is found that slyD mutations cause significant growth rate defects in Escherichia coli B and C backgrounds. Finally, overexpression of slyD causes filamentation of the host. Thus, among the FKBP genes found in organisms across the evolutionary spectrum, slyD is unique in having three distinct drug-independent phenotypes.
authors.affiliation: Department of Biochemistry and Biophysics, Texas A&M University, College Station 77843, USA.
authors.forename: W D
authors.initials: WD
authors.lastname: Roof
authors.forename: H Q
authors.initials: HQ
authors.lastname: Fang
authors.forename: K D
authors.initials: KD
authors.lastname: Young
authors.forename: J
authors.initials: J
authors.lastname: Sun
authors.forename: R
authors.initials: R
authors.lastname: Young
mesh_terms: D000483:Alleles; D000595:Amino Acid Sequence; D000818:Animals; D001483:Base Sequence; D002352:Carrier Proteins / Q000737:chemistry / Q000235:genetics* / Q000378:metabolism; D004252:DNA Mutational Analysis; D004268:DNA-Binding Proteins / Q000737:chemistry / Q000235:genetics*; D004926:Escherichia coli / Q000201:enzymology / Q000235:genetics; D029968:Escherichia coli Proteins; D005798:Genes, Bacterial; D006360:Heat-Shock Proteins / Q000737:chemistry / Q000235:genetics*; D006801:Humans; D008958:Models, Molecular; D008969:Molecular Sequence Data; D009154:Mutation; D019696:Peptidylprolyl Isomerase / Q000737:chemistry / Q000235:genetics* / Q000378:metabolism; D010641:Phenotype; D011487:Protein Conformation; D011817:Rabbits; D022021:Tacrolimus Binding Proteins; D014764:Viral Proteins / Q000235:genetics
chemical_list: D002352:Carrier Proteins; D004268:DNA-Binding Proteins; C029555:E protein, bacteriophage X174; D029968:Escherichia coli Proteins; D006360:Heat-Shock Proteins; C085606:SlyD protein, E coli; D014764:Viral Proteins; D022021:Tacrolimus Binding Proteins; D019696:Peptidylprolyl Isomerase