ABSTRACT

Modeling the Structure of the Nucleosome at 2.5 Angstrom Resolution
Merri Loy, Pellissippi State Technical Community College

Research has shown students develop analytical thinking skills better, and are able to grasp abstract concepts more easily, when hands-on materials are employed in the classroom. This project utilizes the structure elicudated by Dr. Gerald Bunick (University of Tennessee, Knoxville) to build a 3-D scale model of the nucleosome core particle with associated DNA, illustrating several key features of the structure. Each histone has a characteristic histone fold; these are involved in forming histone handshakes between heterogeneous dimers (H2A/H2B and H3/H4). Arginine residues in each of the histones interact with the DNA minor groove, distorting the helix so that it wraps around the core particle. The DNA puts stress on the histone structure, causing the alpha helices to bend, producing asymmetries in the core particle. The histone tails of adjacent particles associate in an unexpected manner in the crystal structure. The completed model will be used in the undergraduate classroom.