1ouz
From Proteopedia
Crystal structure of a mutant IHF (BetaE44A) complexed with a variant H' Site (T44A)
Structural highlights
Function[IHFA_ECOLI] One of the 2 subunits of integration host factor (IHF), a specific DNA-binding protein that functions in genetic recombination as well as in transcriptional and translational control.[1] [2] Plays a crucial role in the lysogenic life cycle of bacteriophage lambda, as it is required not only in the recombination reaction, which inserts lambda DNA into the E.coli chromosome, but also for the synthesis of int and cI repressor, two phage proteins necessary for DNA insertion and repression, respectively. The synthesis of int and cI proteins is regulated indirectly by IHF via translational control of the lambda cII protein.[3] [4] Has an essential role in conjugative DNA transfer (CDT), the unidirectional transfer of ssDNA plasmid from a donor to a recipient cell. It is the central mechanism by which antibiotic resistance and virulence factors are propagated in bacterial populations. Part of the relaxosome, which facilitates a site- and strand-specific cut in the origin of transfer by TraI, at the nic site. Relaxosome formation requires binding of IHF and TraY to the oriT region, which then faciliates binding of TraI.[5] [6] [IHFB_ECOLI] One of the 2 subunits of integration host factor (IHF), a specific DNA-binding protein that functions in genetic recombination as well as in transcriptional and translational control.[7] [8] Plays a crucial role in the lysogenic life cycle of bacteriophage lambda, as it is required not only in the recombination reaction, which inserts lambda DNA into the E.coli chromosome, but also for the synthesis of int and cI repressor, two phage proteins necessary for DNA insertion and repression, respectively. The synthesis of int and cI proteins is regulated indirectly by IHF via translational control of the lambda cII protein.[9] [10] Has an essential role in conjugative DNA transfer (CDT), the unidirectional transfer of ssDNA plasmid from a donor to a recipient cell. It is the central mechanism by which antibiotic resistance and virulence factors are propagated in bacterial populations. Part of the relaxosome, which facilitates a site- and strand-specific cut in the origin of transfer by TraI, at the nic site. Relaxosome formation requires binding of IHF and TraY to the oriT region, which then faciliates binding of TraI.[11] [12] Evolutionary Conservation Check, as determined by ConSurfDB. You may read the explanation of the method and the full data available from ConSurf. Publication Abstract from PubMedIntegration host factor (IHF) is a DNA-bending protein that recognizes its cognate sites through indirect readout. Previous studies have shown that binding of wild-type (WT)-IHF is disrupted by a T to A mutation at the center position of a conserved TTR motif in its binding site, and that substitution of betaGlu44 with Ala prevented IHF from discriminating between A and T at this position. We have determined the crystal structures and relative binding affinities for all combinations of WT-IHF and IHF-betaGlu44Ala bound to the WT and mutant DNAs. Comparison of these structures reveals that DNA twist plays a major role in DNA recognition by IHF, and that this geometric parameter is dependent on the dinucleotide step and not on the bound IHF variant. Integration host factor: putting a twist on protein-DNA recognition.,Lynch TW, Read EK, Mattis AN, Gardner JF, Rice PA J Mol Biol. 2003 Jul 11;330(3):493-502. PMID:12842466[13] From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine. References
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