Open strands adjacent to iterons promote the binding of the replication initiator protein (Rep) of pSC101 to the unit sequence of the iterons in vitro

1996 ◽  
Vol 1305 (3) ◽  
pp. 181-188 ◽  
Author(s):  
Tsukasa Fueki ◽  
Shigeki Sugiura ◽  
Kazuo Yamaguchi
Keyword(s):  
Initiator Protein ◽  
Replication Initiator Protein ◽  
Replication Initiator

scholarly journals Interaction of the Initiator Protein of an IncB Plasmid with Its Origin of DNA Replication

2003 ◽  
Vol 185 (7) ◽  
pp. 2210-2218 ◽  
Author(s):  
T. Betteridge ◽  
J. Yang ◽  
A. J. Pittard ◽  
J. Praszkier
Keyword(s):  
Binding Site ◽  
Sequence Motif ◽  
Initiator Protein ◽  
Origin Of Dna Replication ◽  
Replication Initiator Protein ◽  
Replication Initiator ◽  
Dnaa Binding Site ◽  
Dnaa Box

ABSTRACT The replication initiator protein RepA of the IncB plasmid pMU720 was purified and used in DNase I protection assays in vitro. RepA protected a 68-bp region of the origin of replication of pMU720. This region, which lies immediately downstream of the DnaA box, contains four copies of the sequence motif 5′AANCNGCAA3′. Mutational analyses identified this sequence as the binding site specifically recognized by RepA (the RepA box). Binding of RepA to the RepA boxes was ordered and sequential, with the box closest to the DnaA binding site (box 1) occupied first and the most distant boxes (boxes 3 and 4) occupied last. However, only boxes 1, 2, and 4 were essential for origin activity, with box 3 playing a lesser role. Changing the spacing between box 1 and the other three boxes affected binding of RepA in vitro and origin activity in vivo, indicating that the RepA molecules bound to ori B interact with one another.

scholarly journals Role of RepA and DnaA Proteins in the Opening of the Origin of DNA Replication of an IncB Plasmid

2004 ◽  
Vol 186 (12) ◽  
pp. 3785-3793 ◽  
Author(s):  
T. Betteridge ◽  
J. Yang ◽  
A. J. Pittard ◽  
J. Praszkier
Keyword(s):  
Escherichia Coli ◽  
Binding Sites ◽  
Origin Of Replication ◽  
Initiator Protein ◽  
Origin Of Dna Replication ◽  
Replication Initiator Protein ◽  
Replication Initiator

ABSTRACT The replication initiator protein RepA of the IncB plasmid pMU720 was shown to induce localized unwinding of its cognate origin of replication in vitro. DnaA, the initiator protein of Escherichia coli, was unable to induce localized unwinding of this origin of replication on its own but enhanced the opening generated by RepA. The opened region lies immediately downstream of the last of the three binding sites for RepA (RepA boxes) and covers one turn of DNA helix. A 6-mer sequence, 5′-TCTTAA-3′, which lies within the opened region, was essential for the localized unwinding of the origin in vitro and origin activity in vivo. In addition, efficient unwinding of the origin of replication of pMU720 in vitro required the native positioning of the binding sites for the initiator proteins. Interestingly, binding of RepA to RepA box 1, which is essential for origin activity, was not required for the localized opening of the origin in vitro.

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