Our group is involved in studying both structural (using x-ray absorption spectroscopy) and functional aspects of metal sites in biomolecules. In work designed to elucidate the protein determinants of thermostability and redox potential, we are collaborating with a number of local groups to characterize site-directed and chimeric variants of the metalloprotein rubredoxin. For example, comparative mutational analyses of the rubredoxin from Clostridium pasteurianum with that from Pyrococcus furiosus (a marine hyperthermophilic archaeon that grows at 100°C in hydrothermal vents) are helping determine the protein characteristics that contribute to the impressive thermostability of the latter. 

We are also involved in a biophysical and genetic study of the basal transcription system in P. furiosus. The single transcription system of archaea is homologous to eukaryal class II systems. We have cloned and overexpressed homologs of the eukaryotic TATA-binding protein (TBP, the promoter recognition element) and transcription factor (TF) IIB (binds to TBP/promoter and recruits RNA polymerase). TF(II)B has an N-terminal "Zn ribbon" motif that we have structurally characterized using 2D NMR. We are examining protein-DNA binding and protein-protein interactions to define the topology of the transcription pre-initiation complex in this archaeon.