The respiratory syncytial virus transcription antiterminator M 2-1 is a highly stable, zinc binding tetramer with strong pH-dependent dissociation and a monomeric unfolding intermediate
The human respiratory syncytial virus M 2-1 transcription antiterminator is an essential elongation factor required by the RNA polymerase for effective transcription beyond the first two nonstructural genes. Its exclusive presence in pneumovirus among all paramyxovirus suggests a unique function wit...
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2011
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| Acceso en línea: | https://bibliotecadigital.exactas.uba.ar/collection/paper/document/paper_00062960_v50_n40_p8529_Esperante http://hdl.handle.net/20.500.12110/paper_00062960_v50_n40_p8529_Esperante |
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paper:paper_00062960_v50_n40_p8529_Esperante2023-06-08T14:30:46Z The respiratory syncytial virus transcription antiterminator M 2-1 is a highly stable, zinc binding tetramer with strong pH-dependent dissociation and a monomeric unfolding intermediate Biochemical properties Cellular environment Concentration-dependent Cooperative transitions Dissociation constant Elongation factor Free energy change Global fitting High ionic strength Hydrodynamic Radius Molten globule Monomeric intermediate pH range PH-dependent Protein concentrations Regulatory effects Respiratory syncytial virus RNA polymerase Secondary and tertiary structures Structural change Tetramers Zinc binding Zinc content Dissociation Experiments Free energy Genes Ionic strength Oligomers pH effects RNA Viruses Zinc Transcription monomer protein M2 protein M2-1 RNA RNA polymerase tetramer unclassified drug virus protein zinc alpha helix article atom biochemistry circular dichroism fluorescence spectroscopy hydrodynamics ionic strength light scattering nonhuman pH Pneumovirinae priority journal protein determination protein tertiary structure protein unfolding regulator gene Respiratory syncytial pneumovirus Humans Hydrogen-Ion Concentration Kinetics Peptide Elongation Factors Protein Binding Protein Folding Protein Multimerization Protein Stability Protein Unfolding Respiratory Syncytial Virus Infections Respiratory Syncytial Virus, Human Viral Proteins Zinc Human respiratory syncytial virus Paramyxoviridae Pneumovirus Respiratory syncytial virus The human respiratory syncytial virus M 2-1 transcription antiterminator is an essential elongation factor required by the RNA polymerase for effective transcription beyond the first two nonstructural genes. Its exclusive presence in pneumovirus among all paramyxovirus suggests a unique function within this small genus. With the aim of understanding its biochemical properties, we investigated this α-helical tetramer by making use of a biophysical approach. We found that the tetramer hydrodynamic radius is considerably extended at high ionic strengths and determined its zinc content to be one atom per monomer. Dissociation-unfolding experiments show a fully reversible and concentration-dependent cooperative transition, but secondary and tertiary structural changes are uncoupled at lower protein concentrations. We detect the presence of a monomeric intermediate, which can be classified as a "late molten globule" with substantial secondary and tertiary structure. Global fittings of experiments from three different probes at two M 2-1 concentrations provide a free energy of dissociation-unfolding of -36.8 ± 0.1 kcal mol -1, corresponding to a tight dissociation constant of 10 -28 M 3 at pH 7.0. The tetramer affinity is strongly governed by pH, with a free energy change of 13 kcal mol -1 when pH decreases from 7.0 to 5.0 (K D = 10 -18 M 3). The drastic changes that take place within a pH range compatible with a cellular environment strongly suggest a regulatory effect of pH on M 2-1 structure and biochemical properties, likely affecting transcription and interaction with proteins and RNA. © 2011 American Chemical Society. 2011 https://bibliotecadigital.exactas.uba.ar/collection/paper/document/paper_00062960_v50_n40_p8529_Esperante http://hdl.handle.net/20.500.12110/paper_00062960_v50_n40_p8529_Esperante |
| institution |
Universidad de Buenos Aires |
| institution_str |
I-28 |
| repository_str |
R-134 |
| collection |
Biblioteca Digital - Facultad de Ciencias Exactas y Naturales (UBA) |
| topic |
Biochemical properties Cellular environment Concentration-dependent Cooperative transitions Dissociation constant Elongation factor Free energy change Global fitting High ionic strength Hydrodynamic Radius Molten globule Monomeric intermediate pH range PH-dependent Protein concentrations Regulatory effects Respiratory syncytial virus RNA polymerase Secondary and tertiary structures Structural change Tetramers Zinc binding Zinc content Dissociation Experiments Free energy Genes Ionic strength Oligomers pH effects RNA Viruses Zinc Transcription monomer protein M2 protein M2-1 RNA RNA polymerase tetramer unclassified drug virus protein zinc alpha helix article atom biochemistry circular dichroism fluorescence spectroscopy hydrodynamics ionic strength light scattering nonhuman pH Pneumovirinae priority journal protein determination protein tertiary structure protein unfolding regulator gene Respiratory syncytial pneumovirus Humans Hydrogen-Ion Concentration Kinetics Peptide Elongation Factors Protein Binding Protein Folding Protein Multimerization Protein Stability Protein Unfolding Respiratory Syncytial Virus Infections Respiratory Syncytial Virus, Human Viral Proteins Zinc Human respiratory syncytial virus Paramyxoviridae Pneumovirus Respiratory syncytial virus |
| spellingShingle |
Biochemical properties Cellular environment Concentration-dependent Cooperative transitions Dissociation constant Elongation factor Free energy change Global fitting High ionic strength Hydrodynamic Radius Molten globule Monomeric intermediate pH range PH-dependent Protein concentrations Regulatory effects Respiratory syncytial virus RNA polymerase Secondary and tertiary structures Structural change Tetramers Zinc binding Zinc content Dissociation Experiments Free energy Genes Ionic strength Oligomers pH effects RNA Viruses Zinc Transcription monomer protein M2 protein M2-1 RNA RNA polymerase tetramer unclassified drug virus protein zinc alpha helix article atom biochemistry circular dichroism fluorescence spectroscopy hydrodynamics ionic strength light scattering nonhuman pH Pneumovirinae priority journal protein determination protein tertiary structure protein unfolding regulator gene Respiratory syncytial pneumovirus Humans Hydrogen-Ion Concentration Kinetics Peptide Elongation Factors Protein Binding Protein Folding Protein Multimerization Protein Stability Protein Unfolding Respiratory Syncytial Virus Infections Respiratory Syncytial Virus, Human Viral Proteins Zinc Human respiratory syncytial virus Paramyxoviridae Pneumovirus Respiratory syncytial virus The respiratory syncytial virus transcription antiterminator M 2-1 is a highly stable, zinc binding tetramer with strong pH-dependent dissociation and a monomeric unfolding intermediate |
| topic_facet |
Biochemical properties Cellular environment Concentration-dependent Cooperative transitions Dissociation constant Elongation factor Free energy change Global fitting High ionic strength Hydrodynamic Radius Molten globule Monomeric intermediate pH range PH-dependent Protein concentrations Regulatory effects Respiratory syncytial virus RNA polymerase Secondary and tertiary structures Structural change Tetramers Zinc binding Zinc content Dissociation Experiments Free energy Genes Ionic strength Oligomers pH effects RNA Viruses Zinc Transcription monomer protein M2 protein M2-1 RNA RNA polymerase tetramer unclassified drug virus protein zinc alpha helix article atom biochemistry circular dichroism fluorescence spectroscopy hydrodynamics ionic strength light scattering nonhuman pH Pneumovirinae priority journal protein determination protein tertiary structure protein unfolding regulator gene Respiratory syncytial pneumovirus Humans Hydrogen-Ion Concentration Kinetics Peptide Elongation Factors Protein Binding Protein Folding Protein Multimerization Protein Stability Protein Unfolding Respiratory Syncytial Virus Infections Respiratory Syncytial Virus, Human Viral Proteins Zinc Human respiratory syncytial virus Paramyxoviridae Pneumovirus Respiratory syncytial virus |
| description |
The human respiratory syncytial virus M 2-1 transcription antiterminator is an essential elongation factor required by the RNA polymerase for effective transcription beyond the first two nonstructural genes. Its exclusive presence in pneumovirus among all paramyxovirus suggests a unique function within this small genus. With the aim of understanding its biochemical properties, we investigated this α-helical tetramer by making use of a biophysical approach. We found that the tetramer hydrodynamic radius is considerably extended at high ionic strengths and determined its zinc content to be one atom per monomer. Dissociation-unfolding experiments show a fully reversible and concentration-dependent cooperative transition, but secondary and tertiary structural changes are uncoupled at lower protein concentrations. We detect the presence of a monomeric intermediate, which can be classified as a "late molten globule" with substantial secondary and tertiary structure. Global fittings of experiments from three different probes at two M 2-1 concentrations provide a free energy of dissociation-unfolding of -36.8 ± 0.1 kcal mol -1, corresponding to a tight dissociation constant of 10 -28 M 3 at pH 7.0. The tetramer affinity is strongly governed by pH, with a free energy change of 13 kcal mol -1 when pH decreases from 7.0 to 5.0 (K D = 10 -18 M 3). The drastic changes that take place within a pH range compatible with a cellular environment strongly suggest a regulatory effect of pH on M 2-1 structure and biochemical properties, likely affecting transcription and interaction with proteins and RNA. © 2011 American Chemical Society. |
| title |
The respiratory syncytial virus transcription antiterminator M 2-1 is a highly stable, zinc binding tetramer with strong pH-dependent dissociation and a monomeric unfolding intermediate |
| title_short |
The respiratory syncytial virus transcription antiterminator M 2-1 is a highly stable, zinc binding tetramer with strong pH-dependent dissociation and a monomeric unfolding intermediate |
| title_full |
The respiratory syncytial virus transcription antiterminator M 2-1 is a highly stable, zinc binding tetramer with strong pH-dependent dissociation and a monomeric unfolding intermediate |
| title_fullStr |
The respiratory syncytial virus transcription antiterminator M 2-1 is a highly stable, zinc binding tetramer with strong pH-dependent dissociation and a monomeric unfolding intermediate |
| title_full_unstemmed |
The respiratory syncytial virus transcription antiterminator M 2-1 is a highly stable, zinc binding tetramer with strong pH-dependent dissociation and a monomeric unfolding intermediate |
| title_sort |
respiratory syncytial virus transcription antiterminator m 2-1 is a highly stable, zinc binding tetramer with strong ph-dependent dissociation and a monomeric unfolding intermediate |
| publishDate |
2011 |
| url |
https://bibliotecadigital.exactas.uba.ar/collection/paper/document/paper_00062960_v50_n40_p8529_Esperante http://hdl.handle.net/20.500.12110/paper_00062960_v50_n40_p8529_Esperante |
| _version_ |
1768545076675346432 |