Fis cannot support oriC DNA replication in vitro.
The effects of the histone-like proteins, HU, IHF, and Fis on DNA replication have been examined in vitro using the oriC and pBR322 DNA replication systems. In the oriC system, although low concentrations of HU and IHF stimulated DNA replication, no stimulation was observed upon the addition of Fis. On the contrary, high concentrations of Fis inhibited oriC DNA replication completely. The inhibitory effect of Fis could be overcome when HU, IHF, or RNA polymerase were also present in the reaction mixtures. Unwinding of duplex DNA at the origin correlated with the elevated level of DNA replication. In contrast, only inhibition, rather than stimulation, was observed when these proteins were added to the pBR322 DNA replication system. Thus, the observed dependence on Fis of oriC DNA replication in vivo cannot be attributed to a positive effect on localized DNA unwinding.
Hiasa
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Molecular Biology Program, Memorial Sloan-Kettering Cancer Center, New York, New York 10021.
Marians
K J
KJ
D001426:Bacterial Proteins / Q000494:pharmacology; D002352:Carrier Proteins / Q000494:pharmacology*; D004261:DNA Replication / Q000187:drug effects*; D004269:DNA, Bacterial / Q000096:biosynthesis*; D004268:DNA-Binding Proteins / Q000235:genetics* / Q000494:pharmacology; D035021:Factor For Inversion Stimulation Protein; D034982:Integration Host Factors; D010957:Plasmids
D001426:Bacterial Proteins; D002352:Carrier Proteins; D004269:DNA, Bacterial; D004268:DNA-Binding Proteins; D035021:Factor For Inversion Stimulation Protein; D034982:Integration Host Factors; C040330:histone-like protein HU, bacteria