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Yeast nucleosomal particles: structural and transcriptional properties
M Piñeiro1, C Puerta, E Palacián
1Centro de Biologia Molecular, Universidad Autónoma de Madrid, Spain.
Biochemistry
|June 11, 1991
Summary
Yeast nucleosomal core particles exhibit distinct structural properties compared to chicken cores, particularly in salt dissociation and histone release. These differences, however, do not significantly alter their in vitro transcription capabilities.
Area of Science:
- Molecular Biology
- Biochemistry
- Structural Biology
Background:
- Nucleosomes are fundamental units of DNA packaging in eukaryotes.
- Understanding structural variations in nucleosomes across species is crucial for gene regulation insights.
Purpose of the Study:
- To characterize the structural and functional properties of yeast nucleosomal core particles.
- To compare yeast nucleosomal cores with those from chicken to identify species-specific differences.
Main Methods:
- Thermal denaturation analysis.
- Circular dichroism spectroscopy.
- Enzymatic digestion (DNase I and trypsin).
- Chemical modification (dimethylmaleic anhydride).
Main Results:
- Yeast nucleosomal DNA exhibits a single melting transition at 70°C.
- Yeast nucleosomal cores show higher salt-induced dissociation susceptibility than chicken cores.
- Selective release of histones H2A and H2B was observed upon chemical treatment.
- Despite structural differences, yeast and chicken nucleosomal cores display similar in vitro transcription inhibition by the histone octamer.
Conclusions:
- Significant, though not large, structural distinctions exist between yeast and chicken nucleosomal cores.
- The histone octamer's role in repressing in vitro transcription is conserved, with partial relief upon H2A/H2B loss.