Professor Evangelos Moudrianakis
Department of Biology
John Hopkins University
Baltimore, Maryland

Monday, April 9, 2001
3:00 pm (CT)
3269 Beckman Institute

Abstract

The long polyelectrolyte of the DNA double helix is partially neutralized by its association with histones and is thus converted into a flexible, segmented string of nucleosomes. In this way it can be compacted and stored within the eukaryotic nucleus. Naked DNA molecules can be driven to this compaction state by appropriate manipulation of their micro-environment. The core histone octamer "catalyzes" an analogous transformation under physiological conditions and also adds specificity to the ensemble and the potential for regulation of the genetic activity in chromatin. It thus becomes a gene endoskeleton. We will discuss the architecture of the system, the symmetries that have been conserved through evolution in the histone fold and their thermodynamic implications in DNA-histone interactions. Finally, we will examine the dynamics of the nucleosome and its potential modulations during the on and off cycling of genetic activity.

Tea and coffee will be served in R3151 Beckman Institute at 2:15pm.