Welcome to the Department of Biochemistry, part of the University of Oxford's Medical Sciences Division. We are one of the largest Biochemistry departments in the world and carry out world-class research and teaching. Our researchers come from a range of disciplines and work in a collaborative environment on all aspects of modern molecular and cellular biochemistry. We hope you enjoy reading more about our activities on these pages.
Professor Mark Sansom, Head of Department
Protein sensor turns itself inside out and back again
New research has uncovered the molecular details of how bacteria deal with oxidative stress.
Colin Kleanthous in the department, in collaboration with Jennifer Potts at the University of York and colleagues in Oxford, has published the work in Nature Communications (1). By elucidating the structure and dynamic behaviour of a key protein in a stress-response pathway, they have revealed a new way in which stress sensors in general may function.
Streptomyces colonies. Credit: Mark Buttner, John Innes Centre
All bacteria have sigma factors, proteins that initiate transcription by binding to RNA polymerase. Sigma factors can regulate how bacteria respond to extracellular stresses, which can be diverse – from nutritional cues, to changes in oxidative state or temperature. For some sigma factors, the regulation is imposed by a group of proteins called zinc-binding anti-sigma factors (ZAS). In this system, the ZAS protein rather than the sigma factor responds to stress. ZAS protein and sigma factor are bound in a tight complex in the resting state. When a cue is received, the ZAS protein releases the sigma factor, enabling it to switch on genes that will neutralize the stress.