Structural studies on Neurospora RNA polymerases and associated proteins

Area of Science:

• Molecular Biology
• Biochemistry
• Genetics

Background:

• Neurospora crassa possesses three distinct nuclear RNA polymerases.
• Understanding the structural relationships and interactions of these polymerases is crucial for elucidating gene expression regulation.

Purpose of the Study:

• To investigate the structural homology between the three nuclear RNA polymerases in Neurospora crassa.
• To explore potential in vivo associations between RNA polymerase II and a large nuclear complex.
• To examine the interaction of RNA polymerase III with chromatin.

Main Methods:

• Peptide and immunological analyses were employed to assess structural homology.
• Isolation and characterization of nuclear RNA polymerases and associated complexes.
• Nuclear isolation procedures were optimized for Neurospora.

Main Results:

• Extensive structural homology was identified among the three nuclear RNA polymerases.
• RNA polymerase II was found associated with a 700-kDa nuclear complex of 12 polypeptides.
• Structural similarity was noted between subunits of RNA polymerase II and the 700-kDa complex, suggesting in vivo association.
• Evidence indicates RNA polymerase III may interact with chromatin via its smaller subunits.

Conclusions:

• The three nuclear RNA polymerases in Neurospora crassa share significant structural homology.
• RNA polymerase II is likely associated in vivo with a large nuclear complex.
• RNA polymerase III exhibits potential chromatin interaction mechanisms through its subunits.