• Mike Merrick's Research

Related links

• AT JIC:
• Molecular Microbiology
• ON THE WEB:
• Microbes in Norwich

Curriculum Vitae

• 1970 BSc, Genetics, University of Birmingham, UK
• 1973 PhD, Genetics, University of Birmingham, UK
• 1973 - 1976 Postdoctoral Fellow, John Innes Centre, UK
• 1976 - 1995 Research Scientist, Nitrogen Fixation Laboratory, University of Sussex, UK
• 1995 - present Project Leader, Dept. of Molecular Microbiology, John Innes Centre, UK
• 2007 - Honorary Professor, University of East Anglia, UK
• 2001 - present Associate Head of Department. John Innes Centre, UK

Mike Merrick

Associate Head of Department

Molecular Microbiology

Contact details

mike.merrick@bbsrc.ac.uk

Research interests

Research in my laboratory is focussed on bacterial nitrogen metabolism and the ways in which bacteria control all aspects of that metabolism in response to the availability of fixed nitrogen.  Bacteria can use a wide range of organic and inorganic sources of nitrogen and they must therefore coordinate both the expression of genes and the activities of proteins required for nitrogen metabolism with the availability of nitrogen sources in their environment and with their intracellular nitrogen status (for reviews see: Merrick and Edwards, 1995; Arcondeguy et al, 2001).  

My major interest in recent years has been in the transport of ammonium across cell membranes, which is a process of fundamental importance in almost all living organisms. The means by which ammonium enters cells was unclear until genes encoding ammonium transport (Amt) proteins were isolated in 1994.  Amt proteins are ubiquitous, being found in eubacteria, archaebacteria, fungi, plants, and lower animals.  Members of the Amt family are also present in higher animals including humans where their homologues are the Rhesus proteins.

We have pioneered the use of the Escherichia coli AmtB protein as model system in which to study the mode of action of these integral membrane proteins (Merrick et al., 2006).  The protein can be purified and its 3D X-ray crystal structure has been determined. This has allowed a number of mechanistic questions to be addressed (Javelle et al., 2007).  In bacteria and archeae ammonia flux through Amt proteins is controlled by the GlnK protein. We have elaborated this process in considerable detail and we recently determined the 3D X-ray structure of the AmtB-GlnK complex (Conroy et al., 2007). We have also gained insight into the clinically important Rhesus (Rh) proteins by solving the first Rh protein structure using a rare bacterial Rh protein from Nitrosomonas europeaea (Lupo et al., 2007).