2mw2

Structural highlights

Function

[HHA_ECOLI] Down-regulates hemolysin production and can also stimulate transposition events in vivo. Binds DNA and influences DNA topology in response to environmental stimuli. Involved in persister cell formation, acting downstream of mRNA interferase (toxin) MqsR. Decreases biofilm formation by repressing the transcription of fimbrial genes fimA and ihfA, and by repressing the transcription of tRNAs corresponding to rare codons, which are abundant in type 1 fimbrial genes.^{[1] [2] [3] [4]} [HNS_ECOLI] A DNA-binding protein implicated in transcriptional repression (silencing) as well as in bacterial chromosome organization. H-NS binds tightly to AT-rich dsDNA, increases its thermal stability and inhibits transcription. Also binds to ssDNA and RNA but with a much lower affinity. H-NS has possible histone-like function. May be a global transcriptional regulator through its ability to bind to curved DNA sequences, which are found in regions upstream of a certain subset of promoters. Plays a role in the thermal control of pili and adhesive curli fimbriae production, by inducing transcription of csgD. Represses the CRISPR-cas promoters, permits only weak transcription of the crRNA precursor; its role is antagonized by LeuO. Subject to transcriptional auto-repression. Binds preferentially to the upstream region of its own gene recognizing two segments of DNA on both sides of a bend centered around -150.^{[5] [6] [7] [8]}

References

1. ↑ Nieto JM, Carmona M, Bolland S, Jubete Y, de la Cruz F, Juarez A. The hha gene modulates haemolysin expression in Escherichia coli. Mol Microbiol. 1991 May;5(5):1285-93. PMID:1956303
2. ↑ Barrios AF, Zuo R, Ren D, Wood TK. Hha, YbaJ, and OmpA regulate Escherichia coli K12 biofilm formation and conjugation plasmids abolish motility. Biotechnol Bioeng. 2006 Jan 5;93(1):188-200. PMID:16317765 doi:http://dx.doi.org/10.1002/bit.20681
3. ↑ Garcia-Contreras R, Zhang XS, Kim Y, Wood TK. Protein translation and cell death: the role of rare tRNAs in biofilm formation and in activating dormant phage killer genes. PLoS One. 2008 Jun 11;3(6):e2394. doi: 10.1371/journal.pone.0002394. PMID:18545668 doi:http://dx.doi.org/10.1371/journal.pone.0002394
4. ↑ Kim Y, Wood TK. Toxins Hha and CspD and small RNA regulator Hfq are involved in persister cell formation through MqsR in Escherichia coli. Biochem Biophys Res Commun. 2010 Jan 1;391(1):209-13. doi:, 10.1016/j.bbrc.2009.11.033. Epub 2009 Nov 10. PMID:19909729 doi:10.1016/j.bbrc.2009.11.033
5. ↑ Falconi M, Higgins NP, Spurio R, Pon CL, Gualerzi CO. Expression of the gene encoding the major bacterial nucleotide protein H-NS is subject to transcriptional auto-repression. Mol Microbiol. 1993 Oct;10(2):273-82. PMID:7934818
6. ↑ Ko M, Park C. Two novel flagellar components and H-NS are involved in the motor function of Escherichia coli. J Mol Biol. 2000 Oct 27;303(3):371-82. PMID:11031114 doi:http://dx.doi.org/10.1006/jmbi.2000.4147
7. ↑ Weber H, Pesavento C, Possling A, Tischendorf G, Hengge R. Cyclic-di-GMP-mediated signalling within the sigma network of Escherichia coli. Mol Microbiol. 2006 Nov;62(4):1014-34. Epub 2006 Sep 29. PMID:17010156 doi:http://dx.doi.org/MMI5440
8. ↑ Westra ER, Pul U, Heidrich N, Jore MM, Lundgren M, Stratmann T, Wurm R, Raine A, Mescher M, Van Heereveld L, Mastop M, Wagner EG, Schnetz K, Van Der Oost J, Wagner R, Brouns SJ. H-NS-mediated repression of CRISPR-based immunity in Escherichia coli K12 can be relieved by the transcription activator LeuO. Mol Microbiol. 2010 Sep;77(6):1380-93. doi: 10.1111/j.1365-2958.2010.07315.x., Epub 2010 Aug 18. PMID:20659289 doi:http://dx.doi.org/10.1111/j.1365-2958.2010.07315.x