Biophysical studies of the universally conserved NTPases HflX and YchF

Abstract

Antibiotic resistance is becoming an increasing global health concern. The bacterial protein synthesis machinery, including the ribosome and its associated factors, are the target of over half of the clinically relevant antibiotics currently in use, highlighting the importance of cellular protein production as antibiotic target. The ribosome associated factors HflX and YchF are members of the GTPase superfamily. Their cellular functions are only poorly understood. The overarching goal of this thesis was to determine the location where HflX and YchF bind on the bacterial ribosome. Data presented here confirm that YchF interacts with the ribosomal A-site, while HflX is unique within the GTPase family being able to bind to both the ribosomal A-site and E-site. From this data and subsequent biochemical and biophysical studies, a mechanism for both HflX and YchF function during protein synthesis, specifically under stress conditions, is proposed.