Construction of derivatives of the F plasmid pOX-tra715: characterization of traY and traD mutants that can be complemented in trans.
A derivative of the F plasmid, pOX38-tra715, expresses the entire F tra operon from a foreign promoter (PT7) derived from phage T7. A series of plasmids related to pOX38-tra715 were constructed which carry either deletion mutations or point mutations in traY. When the PT7 promoter was induced, these plasmids expressed the F pilus but were transfer deficient unless TraY was supplied In trans from compatible plasmids. Insertion of a kanamycin-resistance cassette in the traY gene of the pOX38 plasmid, which contains the wild-type PY promoter, resulted in loss of F piliation and transfer ability. Introduction of TraY in trans partially restored piliation and transfer suggesting that TraY has a role in positively regulating the PY promoter, pOX38-tra719-traD411, which contains a chloramphenicol-resistance cassette in place of the kanamycin-resistance cassette in pOX38-tra715 and a mutation in traD, was constructed to demonstrate the utility of this series of plasmids in studying the long (30 kb) F tra operon.
Maneewannakul
K
K
Department of Medical Microbiology and Immunology, Texas A&M University, College Station 77843-1114, USA.
Kathir
P
P
Endley
S
S
Moore
D
D
Manchak
J
J
Frost
L
L
Ippen-Ihler
K
K
D001426:Bacterial Proteins / Q000235:genetics*; D003227:Conjugation, Genetic; D004268:DNA-Binding Proteins / Q000235:genetics*; D004926:Escherichia coli / Q000235:genetics*; D029968:Escherichia coli Proteins; D005144:F Factor; D010861:Fimbriae, Bacterial / Q000378:metabolism; D005816:Genetic Complementation Test; D008565:Membrane Proteins; D016254:Mutagenesis, Insertional; D009876:Operon; D017354:Point Mutation; D017384:Sequence Deletion
D001426:Bacterial Proteins; D004268:DNA-Binding Proteins; D029968:Escherichia coli Proteins; D008565:Membrane Proteins; C064957:traD protein, E coli; C063238:traY protein, E coli; C074281:TraM protein, bacterial