The bacteriophage λ DNA replication protein P inhibits the oriC DNA- and ATP-binding functions of the DNA replication initiator protein DnaA of Escherichia coli

Abstract

Under the condition of expression of λ P protein at lethal level, the oriC DNA-binding activity is significantly affected in wild-type E. coli but not in the rpl mutant. In purified system, the λ P protein inhibits the binding of both oriC DNA and ATP to the wild-type DnaA protein but not to the rpl DnaA protein. We conclude that the λ P protein inhibits the binding of oriC DNA and ATP to the wild-type DnaA protein, which causes the inhibition of host DNA synthesis initiation that ultimately leads to bacterial death. A possible beneficial effect of this interaction of λ P protein with E. coli DNA initiator protein DnaA for phage DNA replication has been proposed.