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Peptides designed from a bacteriophage capsid protein function as synthetic transcription repressors

The bacteriophage capsid protein, Psu (polarity suppression), inhibits the bacterial transcription terminator, Rho. In an effort to find nontraditional antibacterial agents, we previously designed peptides from the Psu C terminus that function as inhibitors of Rho. Here, we demonstrated that these p...

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Autores principales: Sharma, Pankaj V., Jain, Sriyans, Sen, Ranjan
Formato: Online Artículo Texto
Lenguaje:English
Publicado: American Society for Biochemistry and Molecular Biology 2023
Materias:
Acceso en línea:https://www.ncbi.nlm.nih.gov/pmc/articles/PMC10692717/
https://www.ncbi.nlm.nih.gov/pubmed/37865318
http://dx.doi.org/10.1016/j.jbc.2023.105373
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author Sharma, Pankaj V.
Jain, Sriyans
Sen, Ranjan
author_facet Sharma, Pankaj V.
Jain, Sriyans
Sen, Ranjan
author_sort Sharma, Pankaj V.
collection PubMed
description The bacteriophage capsid protein, Psu (polarity suppression), inhibits the bacterial transcription terminator, Rho. In an effort to find nontraditional antibacterial agents, we previously designed peptides from the Psu C terminus that function as inhibitors of Rho. Here, we demonstrated that these peptides have positive surface-charge densities, and they downregulate many genes in Escherichia coli. We hypothesized that these peptides could bind to nucleic acids and repress gene expression. One of these peptides, peptide 33, represses in vitro transcription from the T7A1 and P(lac) promoters efficiently by blocking the access of RNA polymerase to the promoter, a mode of transcription repression akin to many bacterial repressors. In vivo, expressions of the peptides reduce the total RNA level as well as transcription from P(lac) and P(osm) promoters significantly. However, they are less efficient in repressing transcription from the rRNA promoters with a very high turnover of RNA polymerase. The peptide 33 binds to both single and dsDNA as well as to RNA with dissociation constants ranging from 1 to 5 μM exhibiting preferences for the single-stranded DNA and RNAs. These interactions are salt-resistant and not sequence-specific. Interactions with dsDNA are entropy-driven, while it is enthalpy-driven for the ssDNA. This mode of interaction with nucleic acids is similar to many nonspecific ssDNA-binding proteins. Expression of peptide 33 induces cell elongation and impaired cell division, possibly due to the dislodging of the DNA-binding proteins. Overall, we surmised that these synthetic transcription repressors would function like bacterial nucleoid-associated proteins.
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spelling pubmed-106927172023-12-03 Peptides designed from a bacteriophage capsid protein function as synthetic transcription repressors Sharma, Pankaj V. Jain, Sriyans Sen, Ranjan J Biol Chem Research Article Collection: Gene Regulation The bacteriophage capsid protein, Psu (polarity suppression), inhibits the bacterial transcription terminator, Rho. In an effort to find nontraditional antibacterial agents, we previously designed peptides from the Psu C terminus that function as inhibitors of Rho. Here, we demonstrated that these peptides have positive surface-charge densities, and they downregulate many genes in Escherichia coli. We hypothesized that these peptides could bind to nucleic acids and repress gene expression. One of these peptides, peptide 33, represses in vitro transcription from the T7A1 and P(lac) promoters efficiently by blocking the access of RNA polymerase to the promoter, a mode of transcription repression akin to many bacterial repressors. In vivo, expressions of the peptides reduce the total RNA level as well as transcription from P(lac) and P(osm) promoters significantly. However, they are less efficient in repressing transcription from the rRNA promoters with a very high turnover of RNA polymerase. The peptide 33 binds to both single and dsDNA as well as to RNA with dissociation constants ranging from 1 to 5 μM exhibiting preferences for the single-stranded DNA and RNAs. These interactions are salt-resistant and not sequence-specific. Interactions with dsDNA are entropy-driven, while it is enthalpy-driven for the ssDNA. This mode of interaction with nucleic acids is similar to many nonspecific ssDNA-binding proteins. Expression of peptide 33 induces cell elongation and impaired cell division, possibly due to the dislodging of the DNA-binding proteins. Overall, we surmised that these synthetic transcription repressors would function like bacterial nucleoid-associated proteins. American Society for Biochemistry and Molecular Biology 2023-10-20 /pmc/articles/PMC10692717/ /pubmed/37865318 http://dx.doi.org/10.1016/j.jbc.2023.105373 Text en © 2023 The Authors https://creativecommons.org/licenses/by/4.0/This is an open access article under the CC BY license (http://creativecommons.org/licenses/by/4.0/).
spellingShingle Research Article Collection: Gene Regulation
Sharma, Pankaj V.
Jain, Sriyans
Sen, Ranjan
Peptides designed from a bacteriophage capsid protein function as synthetic transcription repressors
title Peptides designed from a bacteriophage capsid protein function as synthetic transcription repressors
title_full Peptides designed from a bacteriophage capsid protein function as synthetic transcription repressors
title_fullStr Peptides designed from a bacteriophage capsid protein function as synthetic transcription repressors
title_full_unstemmed Peptides designed from a bacteriophage capsid protein function as synthetic transcription repressors
title_short Peptides designed from a bacteriophage capsid protein function as synthetic transcription repressors
title_sort peptides designed from a bacteriophage capsid protein function as synthetic transcription repressors
topic Research Article Collection: Gene Regulation
url https://www.ncbi.nlm.nih.gov/pmc/articles/PMC10692717/
https://www.ncbi.nlm.nih.gov/pubmed/37865318
http://dx.doi.org/10.1016/j.jbc.2023.105373
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