查看文章

The heterodimeric integration host factor (IHF) is a site‐specific DNA‐binding and DNA‐bending protein from Escherichia coli. It plays essential roles in a variety of DNA transactions including recombination, transcription and DNA replication. IHF’s ability for concerted binding and bending of DNA is key to its biological function. Here we report the design, characterization and application of a single polypeptide chain IHF, termed scIHF2. In a novel approach for protein engineering, we inserted almost the entire α‐subunit of IHF into the β‐subunit. DNA binding and DNA bending assays revealed that purified wild‐type IHF and scIHF2 behave very similarly. Further, scIHF2 is required for site‐specific integrative recombination by phage λ integrase and for pSC101 replication in a ΔIHF E.coli host. It also triggers site‐specific integrative and excisive recombination in vitro to the same extent as the wild‐type protein. We …