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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.

References

1. ↑ Nelson WC, Howard MT, Sherman JA, Matson SW. The traY gene product and integration host factor stimulate Escherichia coli DNA helicase I-catalyzed nicking at the F plasmid oriT. J Biol Chem. 1995 Nov 24;270(47):28374-80. PMID:7499339
2. ↑ Ragonese H, Haisch D, Villareal E, Choi JH, Matson SW. The F plasmid-encoded TraM protein stimulates relaxosome-mediated cleavage at oriT through an interaction with TraI. Mol Microbiol. 2007 Feb;63(4):1173-84. PMID:17238924 doi:http://dx.doi.org/10.1111/j.1365-2958.2006.05576.x
3. ↑ Nelson WC, Howard MT, Sherman JA, Matson SW. The traY gene product and integration host factor stimulate Escherichia coli DNA helicase I-catalyzed nicking at the F plasmid oriT. J Biol Chem. 1995 Nov 24;270(47):28374-80. PMID:7499339
4. ↑ Ragonese H, Haisch D, Villareal E, Choi JH, Matson SW. The F plasmid-encoded TraM protein stimulates relaxosome-mediated cleavage at oriT through an interaction with TraI. Mol Microbiol. 2007 Feb;63(4):1173-84. PMID:17238924 doi:http://dx.doi.org/10.1111/j.1365-2958.2006.05576.x
5. ↑ Nelson WC, Howard MT, Sherman JA, Matson SW. The traY gene product and integration host factor stimulate Escherichia coli DNA helicase I-catalyzed nicking at the F plasmid oriT. J Biol Chem. 1995 Nov 24;270(47):28374-80. PMID:7499339
6. ↑ Ragonese H, Haisch D, Villareal E, Choi JH, Matson SW. The F plasmid-encoded TraM protein stimulates relaxosome-mediated cleavage at oriT through an interaction with TraI. Mol Microbiol. 2007 Feb;63(4):1173-84. PMID:17238924 doi:http://dx.doi.org/10.1111/j.1365-2958.2006.05576.x
7. ↑ Nelson WC, Howard MT, Sherman JA, Matson SW. The traY gene product and integration host factor stimulate Escherichia coli DNA helicase I-catalyzed nicking at the F plasmid oriT. J Biol Chem. 1995 Nov 24;270(47):28374-80. PMID:7499339
8. ↑ Ragonese H, Haisch D, Villareal E, Choi JH, Matson SW. The F plasmid-encoded TraM protein stimulates relaxosome-mediated cleavage at oriT through an interaction with TraI. Mol Microbiol. 2007 Feb;63(4):1173-84. PMID:17238924 doi:http://dx.doi.org/10.1111/j.1365-2958.2006.05576.x
9. ↑ Nelson WC, Howard MT, Sherman JA, Matson SW. The traY gene product and integration host factor stimulate Escherichia coli DNA helicase I-catalyzed nicking at the F plasmid oriT. J Biol Chem. 1995 Nov 24;270(47):28374-80. PMID:7499339
10. ↑ Ragonese H, Haisch D, Villareal E, Choi JH, Matson SW. The F plasmid-encoded TraM protein stimulates relaxosome-mediated cleavage at oriT through an interaction with TraI. Mol Microbiol. 2007 Feb;63(4):1173-84. PMID:17238924 doi:http://dx.doi.org/10.1111/j.1365-2958.2006.05576.x
11. ↑ Nelson WC, Howard MT, Sherman JA, Matson SW. The traY gene product and integration host factor stimulate Escherichia coli DNA helicase I-catalyzed nicking at the F plasmid oriT. J Biol Chem. 1995 Nov 24;270(47):28374-80. PMID:7499339
12. ↑ Ragonese H, Haisch D, Villareal E, Choi JH, Matson SW. The F plasmid-encoded TraM protein stimulates relaxosome-mediated cleavage at oriT through an interaction with TraI. Mol Microbiol. 2007 Feb;63(4):1173-84. PMID:17238924 doi:http://dx.doi.org/10.1111/j.1365-2958.2006.05576.x
13. ↑ Lynch TW, Read EK, Mattis AN, Gardner JF, Rice PA. Integration host factor: putting a twist on protein-DNA recognition. J Mol Biol. 2003 Jul 11;330(3):493-502. PMID:12842466