| Structural highlights
Function
HDEA_ECOLI Required for optimal acid stress protection. Exhibits a chaperone-like activity only at pH below 3 by suppressing non-specifically the aggregation of denaturated periplasmic proteins. Important for survival of enteric bacteria in the acidic environment of the host stomach. Also promotes the solubilization at neutral pH of proteins that had aggregated in their presence at acidic pHs. May cooperate with other periplasmic chaperones such as DegP and SurA.[1] [2] [3] [4]
Publication Abstract from PubMed
The bacterial acid-resistant chaperone HdeA is a "conditionally disordered" protein that functions at low pH when it undergoes a transition from a well-folded dimer to an unfolded monomer. The dimer dissociation and unfolding processes result in exposure of hydrophobic surfaces that allows binding to a broad range of client proteins. To fully elucidate the chaperone mechanism of HdeA, it is crucial to understand how the activated HdeA interacts with its native substrates during acid stress. Herein, we present a nuclear magnetic resonance study of the pH-dependent HdeA-substrate interactions. Our results show that the activation of HdeA is not only induced by acidification but also regulated by the presence of unfolded substrates. The variable extent of unfolding of substrates differentially regulates the HdeA-substrate interaction, and the binding further affects the HdeA conformation. Finally, we show that HdeA binds its substrates heterogeneously, and the "amphiphilic" model for HdeA-substrate interaction is discussed.
Characterizations of the Interactions between Escherichia coli Periplasmic Chaperone HdeA and Its Native Substrates during Acid Stress.,Yu XC, Yang C, Ding J, Niu X, Hu Y, Jin C Biochemistry. 2017 Oct 31;56(43):5748-5757. doi: 10.1021/acs.biochem.7b00724., Epub 2017 Oct 17. PMID:29016106[5]
From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine.
References
- ↑ Hong W, Jiao W, Hu J, Zhang J, Liu C, Fu X, Shen D, Xia B, Chang Z. Periplasmic protein HdeA exhibits chaperone-like activity exclusively within stomach pH range by transforming into disordered conformation. J Biol Chem. 2005 Jul 22;280(29):27029-34. Epub 2005 May 23. PMID:15911614 doi:http://dx.doi.org/M503934200
- ↑ Kern R, Malki A, Abdallah J, Tagourti J, Richarme G. Escherichia coli HdeB is an acid stress chaperone. J Bacteriol. 2007 Jan;189(2):603-10. Epub 2006 Nov 3. PMID:17085547 doi:http://dx.doi.org/10.1128/JB.01522-06
- ↑ Malki A, Le HT, Milles S, Kern R, Caldas T, Abdallah J, Richarme G. Solubilization of protein aggregates by the acid stress chaperones HdeA and HdeB. J Biol Chem. 2008 May 16;283(20):13679-87. Epub 2008 Mar 20. PMID:18359765 doi:http://dx.doi.org/M800869200
- ↑ Zhang M, Lin S, Song X, Liu J, Fu Y, Ge X, Fu X, Chang Z, Chen PR. A genetically incorporated crosslinker reveals chaperone cooperation in acid resistance. Nat Chem Biol. 2011 Sep 4;7(10):671-7. doi: 10.1038/nchembio.644. PMID:21892184 doi:http://dx.doi.org/10.1038/nchembio.644
- ↑ Yu XC, Yang C, Ding J, Niu X, Hu Y, Jin C. Characterizations of the Interactions between Escherichia coli Periplasmic Chaperone HdeA and Its Native Substrates during Acid Stress. Biochemistry. 2017 Oct 31;56(43):5748-5757. doi: 10.1021/acs.biochem.7b00724., Epub 2017 Oct 17. PMID:29016106 doi:http://dx.doi.org/10.1021/acs.biochem.7b00724
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