The replication initiator protein of plasmid pT181 has sequence-specific endonuclease and topoisomerase-like activities.
AUTOR(ES)
Koepsel, R R
RESUMO
Initiation of pT181 DNA replication specifically requires the plasmid-encoded RepC protein. Here we demonstrate that highly purified RepC protein has sequence-specific endonuclease and topoisomerase-like activities. A maximum sequence of 127 base pairs containing the pT181 origin of replication is required for nicking-closing by RepC protein. RepC introduces a single strand break within the pT181 origin. The nick site has been shown by DNA sequencing to lie between nucleotides 70 and 71 in the bottom strand of the DNA within the origin sequence. This nick site probably corresponds to the start site of pT181 replication. The results presented here suggest that, unlike most other plasmids, pT181 replicates by a rolling circle mechanism.
ACESSO AO ARTIGO
http://www.pubmedcentral.nih.gov/articlerender.fcgi?artid=390784Documentos Relacionados
- Sequence-specific interaction between the replication initiator protein of plasmid pT181 and its origin of replication.
- Plasmids of the pT181 family show replication-specific initiator protein modification.
- Intermediates in plasmid pT181 DNA replication.
- Initiation of rolling-circle replication in pT181 plasmid: initiator protein enhances cruciform extrusion at the origin.
- Control of pT181 replication I. The pT181 copy control function acts by inhibiting the synthesis of a replication protein.