| Structural highlights
Function
[HSLV_ECOLI] Protease subunit of a proteasome-like degradation complex believed to be a general protein degrading machinery. The complex has been shown to be involved in the specific degradation of heat shock induced transcription factors such as RpoH and SulA. In addition, small hydrophobic peptides are also hydrolyzed by HslV. HslV has weak protease activity even in the absence of HslU, but this activity is induced more than 100-fold in the presence of HslU. HslU recognizes protein substrates and unfolds these before guiding them to HslV for hydrolysis. HslV is not believed to degrade folded proteins.[1] [2] [3] [4] [5] [6] [7] [HSLU_ECOLI] ATPase subunit of a proteasome-like degradation complex; this subunit has chaperone activity. The binding of ATP and its subsequent hydrolysis by HslU are essential for unfolding of protein substrates subsequently hydrolyzed by HslV. HslU recognizes the N-terminal part of its protein substrates and unfolds these before they are guided to HslV for hydrolysis.[8] [9] [10] [11] [12] [13] [14]
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 PubMed
HslVU is an ATP-dependent prokaryotic protease complex. Despite detailed crystal and molecular structure determinations of free HslV and HslU, the mechanism of ATP-dependent peptide and protein hydrolysis remained unclear, mainly because the productive complex of HslV and HslU could not be unambiguously identified from the crystal data. In the crystalline complex, the I domains of HslU interact with HslV. Observations based on electron microscopy data were interpreted in the light of the crystal structure to indicate an alternative mode of association with the intermediate domains away from HslV. By generation and analysis of two dozen HslU mutants, we find that the amidolytic and caseinolytic activities of HslVU are quite robust to mutations on both alternative docking surfaces on HslU. In contrast, HslVU activity against the maltose-binding protein-SulA fusion protein depends on the presence of the I domain and is also sensitive to mutations in the N-terminal and C-terminal domains of HslU. Mutational studies around the hexameric pore of HslU seem to show that it is involved in the recognition/translocation of maltose-binding protein-SulA but not of chromogenic small substrates and casein. ATP-binding site mutations, among other things, confirm the essential role of the "sensor arginine" (R393) and the "arginine finger" (R325) in the ATPase action of HslU and demonstrate an important role for E321. Additionally, we report a better refined structure of the HslVU complex crystallized along with resorufin-labeled casein.
Mutational studies on HslU and its docking mode with HslV.,Song HK, Hartmann C, Ramachandran R, Bochtler M, Behrendt R, Moroder L, Huber R Proc Natl Acad Sci U S A. 2000 Dec 19;97(26):14103-8. PMID:11114186[15]
From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine.
See Also
References
- ↑ Yoo SJ, Seol JH, Shin DH, Rohrwild M, Kang MS, Tanaka K, Goldberg AL, Chung CH. Purification and characterization of the heat shock proteins HslV and HslU that form a new ATP-dependent protease in Escherichia coli. J Biol Chem. 1996 Jun 14;271(24):14035-40. PMID:8662828
- ↑ Rohrwild M, Coux O, Huang HC, Moerschell RP, Yoo SJ, Seol JH, Chung CH, Goldberg AL. HslV-HslU: A novel ATP-dependent protease complex in Escherichia coli related to the eukaryotic proteasome. Proc Natl Acad Sci U S A. 1996 Jun 11;93(12):5808-13. PMID:8650174
- ↑ Seol JH, Yoo SJ, Shin DH, Shim YK, Kang MS, Goldberg AL, Chung CH. The heat-shock protein HslVU from Escherichia coli is a protein-activated ATPase as well as an ATP-dependent proteinase. Eur J Biochem. 1997 Aug 1;247(3):1143-50. PMID:9288941
- ↑ Kanemori M, Nishihara K, Yanagi H, Yura T. Synergistic roles of HslVU and other ATP-dependent proteases in controlling in vivo turnover of sigma32 and abnormal proteins in Escherichia coli. J Bacteriol. 1997 Dec;179(23):7219-25. PMID:9393683
- ↑ Seong IS, Oh JY, Yoo SJ, Seol JH, Chung CH. ATP-dependent degradation of SulA, a cell division inhibitor, by the HslVU protease in Escherichia coli. FEBS Lett. 1999 Jul 30;456(1):211-4. PMID:10452560
- ↑ Kanemori M, Yanagi H, Yura T. Marked instability of the sigma(32) heat shock transcription factor at high temperature. Implications for heat shock regulation. J Biol Chem. 1999 Jul 30;274(31):22002-7. PMID:10419524
- ↑ Burton RE, Baker TA, Sauer RT. Nucleotide-dependent substrate recognition by the AAA+ HslUV protease. Nat Struct Mol Biol. 2005 Mar;12(3):245-51. Epub 2005 Feb 6. PMID:15696175 doi:10.1038/nsmb898
- ↑ Yoo SJ, Seol JH, Shin DH, Rohrwild M, Kang MS, Tanaka K, Goldberg AL, Chung CH. Purification and characterization of the heat shock proteins HslV and HslU that form a new ATP-dependent protease in Escherichia coli. J Biol Chem. 1996 Jun 14;271(24):14035-40. PMID:8662828
- ↑ Rohrwild M, Coux O, Huang HC, Moerschell RP, Yoo SJ, Seol JH, Chung CH, Goldberg AL. HslV-HslU: A novel ATP-dependent protease complex in Escherichia coli related to the eukaryotic proteasome. Proc Natl Acad Sci U S A. 1996 Jun 11;93(12):5808-13. PMID:8650174
- ↑ Seol JH, Yoo SJ, Shin DH, Shim YK, Kang MS, Goldberg AL, Chung CH. The heat-shock protein HslVU from Escherichia coli is a protein-activated ATPase as well as an ATP-dependent proteinase. Eur J Biochem. 1997 Aug 1;247(3):1143-50. PMID:9288941
- ↑ Kanemori M, Nishihara K, Yanagi H, Yura T. Synergistic roles of HslVU and other ATP-dependent proteases in controlling in vivo turnover of sigma32 and abnormal proteins in Escherichia coli. J Bacteriol. 1997 Dec;179(23):7219-25. PMID:9393683
- ↑ Seong IS, Oh JY, Yoo SJ, Seol JH, Chung CH. ATP-dependent degradation of SulA, a cell division inhibitor, by the HslVU protease in Escherichia coli. FEBS Lett. 1999 Jul 30;456(1):211-4. PMID:10452560
- ↑ Kanemori M, Yanagi H, Yura T. Marked instability of the sigma(32) heat shock transcription factor at high temperature. Implications for heat shock regulation. J Biol Chem. 1999 Jul 30;274(31):22002-7. PMID:10419524
- ↑ Burton RE, Baker TA, Sauer RT. Nucleotide-dependent substrate recognition by the AAA+ HslUV protease. Nat Struct Mol Biol. 2005 Mar;12(3):245-51. Epub 2005 Feb 6. PMID:15696175 doi:10.1038/nsmb898
- ↑ Song HK, Hartmann C, Ramachandran R, Bochtler M, Behrendt R, Moroder L, Huber R. Mutational studies on HslU and its docking mode with HslV. Proc Natl Acad Sci U S A. 2000 Dec 19;97(26):14103-8. PMID:11114186 doi:10.1073/pnas.250491797
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