Mutational analysis of the activator of late transcription, alt, in the lactococcal bacteriophage TP901-1

Margit Pedersen; Karin Hammer

doi:10.1007/s00705-006-0851-7

Mutational analysis of the activator of late transcription, alt, in the lactococcal bacteriophage TP901-1

Margit Pedersen, Karin Hammer

Biocomplexity

1 Citation (Scopus)

Abstract

An activator protein, Alt, synthesized during the early state of lytic infection is required for transcription of the late operon in the lactococcal phage TP901-1. In order to identify amino acid residues in the Alt protein required for activation of the TP901-1 late promoter, Plate, hydroxylamine mutagenesis was performed, resulting in almost saturating mutagenesis of alt. Twenty-three different non-functional alt alleles containing one, and in one case two amino acid exchanges were isolated and analyzed. Eight of the twenty-three mutant proteins were still able to activate the Plate promoter to some extent. Our results show that alt encodes a protein of 16.7 kDa and that the last fourteen amino acids in the C-terminal part of the protein are required for activation of the Plate promoter. By combining sequence analysis with experimental data we suggest that the C-terminal half of the Alt protein contains a helix-turn-helix-like motif involved in DNA binding. We also propose that the C-terminal half of the Alt protein may be involved in interactions with the bacterial RNA polymerase, whereas the N-terminal half of the protein is proposed to be important for the overall protein structure.

Original language	English
Journal	Archives of Virology
Volume	152
Issue number	2
Pages (from-to)	305-320
Number of pages	15
ISSN	0304-8608
DOIs	https://doi.org/10.1007/s00705-006-0851-7
Publication status	Published - 27 Oct 2007

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10.1007/s00705-006-0851-7

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@article{12aad905288f4aa2b5e9ea46a6a8bc75,

title = "Mutational analysis of the activator of late transcription, alt, in the lactococcal bacteriophage TP901-1",

abstract = "An activator protein, Alt, synthesized during the early state of lytic infection is required for transcription of the late operon in the lactococcal phage TP901-1. In order to identify amino acid residues in the Alt protein required for activation of the TP901-1 late promoter, Plate, hydroxylamine mutagenesis was performed, resulting in almost saturating mutagenesis of alt. Twenty-three different non-functional alt alleles containing one, and in one case two amino acid exchanges were isolated and analyzed. Eight of the twenty-three mutant proteins were still able to activate the Plate promoter to some extent. Our results show that alt encodes a protein of 16.7 kDa and that the last fourteen amino acids in the C-terminal part of the protein are required for activation of the Plate promoter. By combining sequence analysis with experimental data we suggest that the C-terminal half of the Alt protein contains a helix-turn-helix-like motif involved in DNA binding. We also propose that the C-terminal half of the Alt protein may be involved in interactions with the bacterial RNA polymerase, whereas the N-terminal half of the protein is proposed to be important for the overall protein structure.",

author = "Margit Pedersen and Karin Hammer",

year = "2007",

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journal = "Archiv fur die gesamte Virusforschung",

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TY - JOUR

T1 - Mutational analysis of the activator of late transcription, alt, in the lactococcal bacteriophage TP901-1

AU - Pedersen, Margit

AU - Hammer, Karin

PY - 2007/10/27

Y1 - 2007/10/27

N2 - An activator protein, Alt, synthesized during the early state of lytic infection is required for transcription of the late operon in the lactococcal phage TP901-1. In order to identify amino acid residues in the Alt protein required for activation of the TP901-1 late promoter, Plate, hydroxylamine mutagenesis was performed, resulting in almost saturating mutagenesis of alt. Twenty-three different non-functional alt alleles containing one, and in one case two amino acid exchanges were isolated and analyzed. Eight of the twenty-three mutant proteins were still able to activate the Plate promoter to some extent. Our results show that alt encodes a protein of 16.7 kDa and that the last fourteen amino acids in the C-terminal part of the protein are required for activation of the Plate promoter. By combining sequence analysis with experimental data we suggest that the C-terminal half of the Alt protein contains a helix-turn-helix-like motif involved in DNA binding. We also propose that the C-terminal half of the Alt protein may be involved in interactions with the bacterial RNA polymerase, whereas the N-terminal half of the protein is proposed to be important for the overall protein structure.

AB - An activator protein, Alt, synthesized during the early state of lytic infection is required for transcription of the late operon in the lactococcal phage TP901-1. In order to identify amino acid residues in the Alt protein required for activation of the TP901-1 late promoter, Plate, hydroxylamine mutagenesis was performed, resulting in almost saturating mutagenesis of alt. Twenty-three different non-functional alt alleles containing one, and in one case two amino acid exchanges were isolated and analyzed. Eight of the twenty-three mutant proteins were still able to activate the Plate promoter to some extent. Our results show that alt encodes a protein of 16.7 kDa and that the last fourteen amino acids in the C-terminal part of the protein are required for activation of the Plate promoter. By combining sequence analysis with experimental data we suggest that the C-terminal half of the Alt protein contains a helix-turn-helix-like motif involved in DNA binding. We also propose that the C-terminal half of the Alt protein may be involved in interactions with the bacterial RNA polymerase, whereas the N-terminal half of the protein is proposed to be important for the overall protein structure.

U2 - 10.1007/s00705-006-0851-7

DO - 10.1007/s00705-006-0851-7

M3 - Journal article

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JO - Archiv fur die gesamte Virusforschung

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