Premium
Effects of purified SeqA protein on oriC ‐dependent DNA replication in vitro
Author(s) -
Wold Sture,
Boye Erik,
Slater Steven,
Kleckner Nancy,
Skarstad Kirsten
Publication year - 1998
Publication title -
the embo journal
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 7.484
H-Index - 392
eISSN - 1460-2075
pISSN - 0261-4189
DOI - 10.1093/emboj/17.14.4158
Subject(s) - seqa protein domain , biology , dnaa , plasmid , origin of replication , microbiology and biotechnology , in vitro , dna replication , replication (statistics) , genetics , dna , virology
In vivo studies suggest that the Escherichia coli SeqA protein modulates replication initiation in two ways: by delaying initiation and by sequestering newly replicated origins from undergoing re‐replication. As a first approach towards understanding the biochemical bases for these effects, we have examined the effects of purified SeqA protein on replication reactions performed in vitro on an oriC plasmid. Our results demonstrate that SeqA directly affects the biochemical events occurring at oriC . First, SeqA inhibits formation of the pre‐priming complex. Secondly, SeqA can inhibit replication from an established pre‐priming complex, without disrupting the complex. Thirdly, SeqA alters the dependence of the replication system on DnaA protein concentration, stimulating replication at low concentrations of DnaA. Our data suggest that SeqA participates in the assembly of initiation‐competent complexes at oriC and, at a later stage, influences the behaviour of these complexes.