Oxidization without substrate unfolding triggers proteolysis of the peroxide-sensor, PerR
Peroxide operon regulator (PerR) is a broadly conserved hydrogen peroxide sensor in bacteria, and oxidation of PerR at its regulatory metal-binding site is considered irreversible. Here, we tested whether this oxidation specifically targets PerR for proteolysis. We find that oxidizing conditions sti...
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| Format: | Article |
| Language: | en_US |
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National Academy of Sciences (U.S.)
2017
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| Online Access: | http://hdl.handle.net/1721.1/106300 |
| _version_ | 1826212450037399552 |
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| author | Ahn, Bo-Eun Baker, Tania |
| author2 | Massachusetts Institute of Technology. Department of Biology |
| author_facet | Massachusetts Institute of Technology. Department of Biology Ahn, Bo-Eun Baker, Tania |
| author_sort | Ahn, Bo-Eun |
| collection | MIT |
| description | Peroxide operon regulator (PerR) is a broadly conserved hydrogen peroxide sensor in bacteria, and oxidation of PerR at its regulatory metal-binding site is considered irreversible. Here, we tested whether this oxidation specifically targets PerR for proteolysis. We find that oxidizing conditions stimulate PerR degradation in vivo, and LonA is the principal AAA+ (ATPases associated with diverse cellular activities) protease that degrades PerR. Degradation of PerR by LonA is recapitulated in vitro, and biochemical dissection of this degradation reveals that the presence of regulatory metal and PerR-binding DNA dramatically extends the half-life of the protein. We identified a LonA-recognition site critical for oxidation-controlled PerR turnover. Key residues for LonA-interaction are exposed to solvent in PerR lacking metal, but are buried in the metal-bound form. Furthermore, one residue critical for Lon recognition is also essential for specific DNA-binding by PerR, thus explaining how both the metal and DNA ligands prevent PerR degradation. This ligand-controlled allosteric mechanism for protease recognition provides a compelling explanation for how the oxidation-induced conformational change in PerR triggers degradation. Interestingly, the critical residues recognized by LonA and exposed by oxidation do not function as a degron, because they are not sufficient to convert a nonsubstrate protein into a LonA substrate. Rather, these residues are a conformation-discriminator sequence, which must work together with other residues in PerR to evoke efficient degradation. This mechanism provides a useful example of how other proteins with only mild or localized oxidative damage can be targeted for degradation without the need for extensive oxidation-dependent protein denaturation. |
| first_indexed | 2024-09-23T15:22:03Z |
| format | Article |
| id | mit-1721.1/106300 |
| institution | Massachusetts Institute of Technology |
| language | en_US |
| last_indexed | 2024-09-23T15:22:03Z |
| publishDate | 2017 |
| publisher | National Academy of Sciences (U.S.) |
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| spelling | mit-1721.1/1063002022-10-02T02:29:12Z Oxidization without substrate unfolding triggers proteolysis of the peroxide-sensor, PerR Ahn, Bo-Eun Baker, Tania Massachusetts Institute of Technology. Department of Biology Ahn, Bo-Eun Baker, Tania Peroxide operon regulator (PerR) is a broadly conserved hydrogen peroxide sensor in bacteria, and oxidation of PerR at its regulatory metal-binding site is considered irreversible. Here, we tested whether this oxidation specifically targets PerR for proteolysis. We find that oxidizing conditions stimulate PerR degradation in vivo, and LonA is the principal AAA+ (ATPases associated with diverse cellular activities) protease that degrades PerR. Degradation of PerR by LonA is recapitulated in vitro, and biochemical dissection of this degradation reveals that the presence of regulatory metal and PerR-binding DNA dramatically extends the half-life of the protein. We identified a LonA-recognition site critical for oxidation-controlled PerR turnover. Key residues for LonA-interaction are exposed to solvent in PerR lacking metal, but are buried in the metal-bound form. Furthermore, one residue critical for Lon recognition is also essential for specific DNA-binding by PerR, thus explaining how both the metal and DNA ligands prevent PerR degradation. This ligand-controlled allosteric mechanism for protease recognition provides a compelling explanation for how the oxidation-induced conformational change in PerR triggers degradation. Interestingly, the critical residues recognized by LonA and exposed by oxidation do not function as a degron, because they are not sufficient to convert a nonsubstrate protein into a LonA substrate. Rather, these residues are a conformation-discriminator sequence, which must work together with other residues in PerR to evoke efficient degradation. This mechanism provides a useful example of how other proteins with only mild or localized oxidative damage can be targeted for degradation without the need for extensive oxidation-dependent protein denaturation. United States. Public Health Service (Grant GM049224) Howard Hughes Medical Institute 2017-01-09T19:31:12Z 2017-01-09T19:31:12Z 2016-01 2015-07 Article http://purl.org/eprint/type/JournalArticle 0027-8424 1091-6490 http://hdl.handle.net/1721.1/106300 Ahn, Bo-Eun, and Tania A. Baker. “Oxidization without Substrate Unfolding Triggers Proteolysis of the Peroxide-Sensor, PerR.” Proceedings of the National Academy of Sciences 113.1 (2016): E23–E31. © 2016 National Academy of Sciences en_US http://dx.doi.org/10.1073/pnas.1522687112 Proceedings of the National Academy of Sciences Article is made available in accordance with the publisher's policy and may be subject to US copyright law. Please refer to the publisher's site for terms of use. application/pdf National Academy of Sciences (U.S.) PNAS |
| spellingShingle | Ahn, Bo-Eun Baker, Tania Oxidization without substrate unfolding triggers proteolysis of the peroxide-sensor, PerR |
| title | Oxidization without substrate unfolding triggers proteolysis of the peroxide-sensor, PerR |
| title_full | Oxidization without substrate unfolding triggers proteolysis of the peroxide-sensor, PerR |
| title_fullStr | Oxidization without substrate unfolding triggers proteolysis of the peroxide-sensor, PerR |
| title_full_unstemmed | Oxidization without substrate unfolding triggers proteolysis of the peroxide-sensor, PerR |
| title_short | Oxidization without substrate unfolding triggers proteolysis of the peroxide-sensor, PerR |
| title_sort | oxidization without substrate unfolding triggers proteolysis of the peroxide sensor perr |
| url | http://hdl.handle.net/1721.1/106300 |
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