| |
Research Description:
My previous (prior to 2004) research efforts focused on developing methods and algorithms
for predicting protein structures from amino acid sequences, predicting kinetics of protein folding,
analyzing mechanisms of molecular recognition, and predicting binding affinities
and specificities of protein-protein interactions.
The goal of my current (2004-) research is to predict gene regulation on a whole-genome scale,
including the variation that is influenced by cell type, environmental signals, developmental stage,
and disease state. Broadly speaking, I seek to improve our current understanding of the
"transcriptional and post-transcriptional regulatory code" that links the DNA sequence
with gene expression levels. To this end, I and the members of my lab are currently
pursuing several projects:
- Studies of chromatin structure and its effect on gene regulation (including both individual
nucleosome positions and higher-order chromatin structures). In eukaryotic genomes, nucleosomes
(histone-DNA complexes) function to compact DNA and to regulate access to it both by simple physical
occlusion and by providing the substrate for numerous covalent epigenetic tags.
We use sequence-dependent DNA mechanics models as well as techniques borrowed from statistical mechanics
and polymer physics to predict nucleosome positions both in vitro (where they are determined
by the DNA sequence alone) and in vivo, where chromatin structure is dynamically modified via
competition with other DNA-binding factors and the action of chromatin remodeling enzymes. Our
computational models are guided by high-throughput measurements of nucleosome positions.
- Biophysical models of protein evolution. Amino acid substitutions that have accumulated
in homologous proteins in the course of evolution provide important clues to their stability
and function. We are developing descriptions of protein energetics in which observed correlations
between amino acid mutations at different positions are ascribed to both protein energetics
(e.g. physical coupling between two amino acids in the protein molecule) and
compensatory evolutionary effects.
- Prediction of protein-DNA energetics (amino acid - DNA basepair recognition code)
using a combination of protein-DNA structural data and high-throughput
assays designed to probe protein-DNA interactions on the genomic scale.
|