Mike Merrick, John Innes Centre, Norwich, presents this lecture for the Division of Biology on; “Ammonia Channels from Bacteria to Man”
Abstract: The Amt proteins constitute a family of integral membrane channels that is conserved across all domains of life. Amt proteins are ubiquitous in archaea, eubacteria, fungi and plants, whilst in animals they are represented by the closely related Rhesus proteins. This seminar will focus on the AmtB protein from Escherichia coli which we have developed as a model system for the analysis of ammonium transport. I will discuss current studies on the mode of action of Amt proteins and relate these to the 3D crystal structure of AmtB. I will also describe recent studies from our laboratory on the way in which the activity of E. coli AmtB is regulated by complex formation with the cytoplasmic signal transduction protein GlnK. The role of these two proteins in integrating extracellular ammonium availability with intracellular nitrogen metabolism in bacteria will be discussed. Finally I will describe recent studies on a bacterial Rhesus protein that shed new light on these clinically important proteins.