Interaction of the Bacillus subtilis DnaA-like protein with the Escherichia coli DnaA protein.
Plasmids carrying the intact Bacillus subtilis dnaA-like gene and two reciprocal hybrids between the B. subtilis and Escherichia coli dnaA genes were constructed. None of the plasmids could transform wild-type E. coli cells unless the cells contained surplus E. coli DnaA protein (DnaAEc). A dnaA (Ts) strain integratively suppressed by the plasmid R1 origin could be transformed by plasmids carrying either the B. subtilis gene (dnaABs) or a hybrid gene containing the amino terminus of the E. coli gene and the carboxyl terminus of the B. subtilis gene (dnaAEc/Bs). In cells with surplus E. coli DnaA protein, expression of the E. coli dnaA gene was derepressed by the B. subtilis DnaA protein and by the hybrid DnaAEc/Bs protein, whereas it was strongly repressed by the reciprocal hybrid protein DnaABs/Ec. The plasmids carrying the different dnaA genes probably all interfere with initiation of chromosome replication in E. coli by decreasing the E. coli DnaA protein concentration to a limiting level. The DnaABs and the DnaAEc/Bs proteins effect this decrease possibly by forming inactive oligomeric proteins, while the DnaABs/Ec protein may decrease dnaAEc gene expression.
Andrup
L
L
Department of Microbiology, Technical University of Denmark, Lyngby.
Atlung
T
T
Ogasawara
N
N
Yoshikawa
H
H
Hansen
F G
FG
D001412:Bacillus subtilis / Q000235:genetics*; D001426:Bacterial Proteins / Q000235:genetics*; D003001:Cloning, Molecular; D004261:DNA Replication; D004274:DNA, Recombinant; D004926:Escherichia coli / Q000235:genetics*; D005786:Gene Expression Regulation; D014170:Transformation, Genetic
D001426:Bacterial Proteins; D004274:DNA, Recombinant