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Bacteriophage 434 Hex Protein Prevents RecA-Mediated Repressor Autocleavage

In a λ(imm434) lysogen, two proteins are expressed from the integrated prophage. Both are encoded by the same mRNA whose transcription initiates at the P(RM) promoter. One protein is the 434 repressor, needed for the establishment and maintenance of lysogeny. The other is Hex which is translated fro...

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Autores principales: Shkilnyj, Paul, Colon, Michael P., Koudelka, Gerald B.
Formato: Online Artículo Texto
Lenguaje:English
Publicado: MDPI 2013
Materias:
Acceso en línea:https://www.ncbi.nlm.nih.gov/pmc/articles/PMC3564112/
https://www.ncbi.nlm.nih.gov/pubmed/23303392
http://dx.doi.org/10.3390/v5010111
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author Shkilnyj, Paul
Colon, Michael P.
Koudelka, Gerald B.
author_facet Shkilnyj, Paul
Colon, Michael P.
Koudelka, Gerald B.
author_sort Shkilnyj, Paul
collection PubMed
description In a λ(imm434) lysogen, two proteins are expressed from the integrated prophage. Both are encoded by the same mRNA whose transcription initiates at the P(RM) promoter. One protein is the 434 repressor, needed for the establishment and maintenance of lysogeny. The other is Hex which is translated from an open reading frame that apparently partially overlaps the 434 repressor coding region. In the wild type host, disruption of the gene encoding Hex destabilizes λ(imm434) lysogens. However, the hex mutation has no effect on lysogen stability in a recA(−) host. These observations suggest that Hex functions by modulating the ability of RecA to stimulate 434 repressor autocleavage. We tested this hypothesis by identifying and purifying Hex to determine if this protein inhibited RecA‑stimulated autocleavage of 434 repressor in vitro. Our results show that in vitro a fragment of Hex prevents RecA-stimulated autocleavage of 434 repressor, as well as the repressors of the closely related phage P22. Surprisingly, Hex does not prevent RecA‑stimulated autocleavage of phage lambda repressor, nor the E. coli LexA repressor.
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spelling pubmed-35641122013-02-11 Bacteriophage 434 Hex Protein Prevents RecA-Mediated Repressor Autocleavage Shkilnyj, Paul Colon, Michael P. Koudelka, Gerald B. Viruses Article In a λ(imm434) lysogen, two proteins are expressed from the integrated prophage. Both are encoded by the same mRNA whose transcription initiates at the P(RM) promoter. One protein is the 434 repressor, needed for the establishment and maintenance of lysogeny. The other is Hex which is translated from an open reading frame that apparently partially overlaps the 434 repressor coding region. In the wild type host, disruption of the gene encoding Hex destabilizes λ(imm434) lysogens. However, the hex mutation has no effect on lysogen stability in a recA(−) host. These observations suggest that Hex functions by modulating the ability of RecA to stimulate 434 repressor autocleavage. We tested this hypothesis by identifying and purifying Hex to determine if this protein inhibited RecA‑stimulated autocleavage of 434 repressor in vitro. Our results show that in vitro a fragment of Hex prevents RecA-stimulated autocleavage of 434 repressor, as well as the repressors of the closely related phage P22. Surprisingly, Hex does not prevent RecA‑stimulated autocleavage of phage lambda repressor, nor the E. coli LexA repressor. MDPI 2013-01-09 /pmc/articles/PMC3564112/ /pubmed/23303392 http://dx.doi.org/10.3390/v5010111 Text en © 2013 by the authors; licensee MDPI, Basel, Switzerland. http://creativecommons.org/licenses/by/3.0/ This article is an open-access article distributed under the terms and conditions of the Creative Commons Attribution license (http://creativecommons.org/licenses/by/3.0/).
spellingShingle Article
Shkilnyj, Paul
Colon, Michael P.
Koudelka, Gerald B.
Bacteriophage 434 Hex Protein Prevents RecA-Mediated Repressor Autocleavage
title Bacteriophage 434 Hex Protein Prevents RecA-Mediated Repressor Autocleavage
title_full Bacteriophage 434 Hex Protein Prevents RecA-Mediated Repressor Autocleavage
title_fullStr Bacteriophage 434 Hex Protein Prevents RecA-Mediated Repressor Autocleavage
title_full_unstemmed Bacteriophage 434 Hex Protein Prevents RecA-Mediated Repressor Autocleavage
title_short Bacteriophage 434 Hex Protein Prevents RecA-Mediated Repressor Autocleavage
title_sort bacteriophage 434 hex protein prevents reca-mediated repressor autocleavage
topic Article
url https://www.ncbi.nlm.nih.gov/pmc/articles/PMC3564112/
https://www.ncbi.nlm.nih.gov/pubmed/23303392
http://dx.doi.org/10.3390/v5010111
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