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A Substrate Radical Intermediate in Catalysis by the Antibiotic Resistance Protein Cfr
Cfr-dependent methylation of C8 of adenosine 2503 (A2503) in 23S rRNA confers bacterial resistance to an array of clinically important antibiotics that target the large subunit of the ribosome, including the synthetic oxazolidinone antibiotic linezolid. The key element of the proposed mechanism for...
Autores principales: | , , , , , |
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Formato: | Online Artículo Texto |
Lenguaje: | English |
Publicado: |
2013
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Materias: | |
Acceso en línea: | https://www.ncbi.nlm.nih.gov/pmc/articles/PMC3897224/ https://www.ncbi.nlm.nih.gov/pubmed/23644479 http://dx.doi.org/10.1038/nchembio.1251 |
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author | Grove, Tyler L. Livada, Jovan Schwalm, Erica L. Green, Michael T. Booker, Squire J. Silakov, Alexey |
author_facet | Grove, Tyler L. Livada, Jovan Schwalm, Erica L. Green, Michael T. Booker, Squire J. Silakov, Alexey |
author_sort | Grove, Tyler L. |
collection | PubMed |
description | Cfr-dependent methylation of C8 of adenosine 2503 (A2503) in 23S rRNA confers bacterial resistance to an array of clinically important antibiotics that target the large subunit of the ribosome, including the synthetic oxazolidinone antibiotic linezolid. The key element of the proposed mechanism for Cfr, a radical S-adenosylmethionine (SAM) enzyme, is the addition of a methylene radical — generated by hydrogen-atom abstraction from the methyl group of an S-methylated cysteine residue (mCys) — onto C8 of A2503 to form a protein – nucleic acid cross-linked species containing an unpaired electron. Herein we use continuous-wave and pulsed electron paramagnetic resonance (EPR) techniques to provide direct spectroscopic evidence for this intermediate, showing a spin-delocalized radical with maximum spin density at N7 of the adenine ring. In addition, we use rapid-freeze quench EPR to show that the radical forms and decays with rate constants that are consistent with the rate of formation of the methylated product. |
format | Online Article Text |
id | pubmed-3897224 |
institution | National Center for Biotechnology Information |
language | English |
publishDate | 2013 |
record_format | MEDLINE/PubMed |
spelling | pubmed-38972242014-01-21 A Substrate Radical Intermediate in Catalysis by the Antibiotic Resistance Protein Cfr Grove, Tyler L. Livada, Jovan Schwalm, Erica L. Green, Michael T. Booker, Squire J. Silakov, Alexey Nat Chem Biol Article Cfr-dependent methylation of C8 of adenosine 2503 (A2503) in 23S rRNA confers bacterial resistance to an array of clinically important antibiotics that target the large subunit of the ribosome, including the synthetic oxazolidinone antibiotic linezolid. The key element of the proposed mechanism for Cfr, a radical S-adenosylmethionine (SAM) enzyme, is the addition of a methylene radical — generated by hydrogen-atom abstraction from the methyl group of an S-methylated cysteine residue (mCys) — onto C8 of A2503 to form a protein – nucleic acid cross-linked species containing an unpaired electron. Herein we use continuous-wave and pulsed electron paramagnetic resonance (EPR) techniques to provide direct spectroscopic evidence for this intermediate, showing a spin-delocalized radical with maximum spin density at N7 of the adenine ring. In addition, we use rapid-freeze quench EPR to show that the radical forms and decays with rate constants that are consistent with the rate of formation of the methylated product. 2013-05-05 2013-07 /pmc/articles/PMC3897224/ /pubmed/23644479 http://dx.doi.org/10.1038/nchembio.1251 Text en Users may view, print, copy, download and text and data- mine the content in such documents, for the purposes of academic research, subject always to the full Conditions of use: http://www.nature.com/authors/editorial_policies/license.html#terms |
spellingShingle | Article Grove, Tyler L. Livada, Jovan Schwalm, Erica L. Green, Michael T. Booker, Squire J. Silakov, Alexey A Substrate Radical Intermediate in Catalysis by the Antibiotic Resistance Protein Cfr |
title | A Substrate Radical Intermediate in Catalysis by the Antibiotic Resistance Protein Cfr |
title_full | A Substrate Radical Intermediate in Catalysis by the Antibiotic Resistance Protein Cfr |
title_fullStr | A Substrate Radical Intermediate in Catalysis by the Antibiotic Resistance Protein Cfr |
title_full_unstemmed | A Substrate Radical Intermediate in Catalysis by the Antibiotic Resistance Protein Cfr |
title_short | A Substrate Radical Intermediate in Catalysis by the Antibiotic Resistance Protein Cfr |
title_sort | substrate radical intermediate in catalysis by the antibiotic resistance protein cfr |
topic | Article |
url | https://www.ncbi.nlm.nih.gov/pmc/articles/PMC3897224/ https://www.ncbi.nlm.nih.gov/pubmed/23644479 http://dx.doi.org/10.1038/nchembio.1251 |
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