We are using the simple, well-characterized, and genetically facile bacterium E. coli as a model system to study the molecular details of protein translocation across the plasma membrane. Our major focus is on SecA ATPase, a motor protein that binds preproteins and the translocon component SecYEG, and which undergoes ATP-driven conformational cycles at the membrane that promote the stepwise translocation of proteins across this membrane layer. Genetic, biochemical and biophysical approaches are being utilized along with our recent crystal structure of SecA protein in order to elucidate a number of important questions in this system.
Reexamination of the Role of the Amino Terminus of SecA in Promoting its Dimerization and Functional State, Journal of Bacteriology (2008)
In Vivo Membrane Topology of Escherichia Coli SecA ATPase Reveals Extensive Periplasmic Exposure of Multiple Functionally Important Domains Clustering on One Face of SecA, Journal of Biological Chemistry (2007)
SecA Dimer Cross-linked at its Subunit Interface is Functional for Protein Translocation, Journal of Bacteriology (2006)
SecA facilitates protein transport across the eubacterial plasma membrane by its association with cargo proteins...
Dimeric SecA is Essential for Protein Translocation, Proceedings of the National Academy of Sciences (2005)
SecA facilitates bacterial protein translocation by its association with presecretory or membrane proteins and the...
Role of a Conserved Glutamate Residue in the Escherichia coli SecA ATPase Mechanism, Journal of Biological Chemistry (2005)
Escherichia coli SecA uses ATP to drive the transport of proteins across cell membranes. Glutamate...