Dr Nicholas Edward Dixon
Position: Senior Fellow, Research School of Chemistry, Australian National University
Affiliation: Research School of Chemistry, Australian National University
Phone: +61 (02) 6125 4391
Dr Dixon's research career has centred on developing understanding of the structures and functions of enzymes and proteins. He has made seminal contributions to research on binuclear metallohydrolases. As a PhD student, he discovered jack bean urease to be the first example of a natural nickel metalloenzyme, and as a result of careful mechanistic studies, proposed that the nickel ions were close together annd that both participated in the reaction. This novel mechanism turned out subsequently to be essentially true for urease, and to extend in a general sense to other binuclear metallohydrolases. Recent structures determined with collaborators and mechanistic studies showed that both aminopeptidase P and the proofreading subunit of DNA polymerase III have similar mechanisms. As a postdoc at ANU, he developed new and general methods for preparation of metal complexes and used them to study mechanisms of reactions of coordinated ligands as models for metalloenzymes. With Arthur Kornberg at Stanford, he was a key player in reconstitution of initiation of chromosomal DNA replication with purified proteins. He identified a novel factor required for this (protein HU). Since appointment to ANU, he has continued work on the structures and mechanisms of DNA replication proteins. His group has overproduced and purified more than fifty replication and other proteins, and used crystallography and NMR (in collaboration) to solve many important structures. Most significantly, Dixon initiated an international collaborative effort aimed at determining structures of the major hexameric replicative helicase (DnaB) and its complexes with other proteins, and he has recently defined the structural basis for proofreading by the replicative polymerase during DNA replication. Over the past few years, he initiated an adventurous long-term project involving development of selection and library construction methods for the directed molecular evolution of new protein structures and functions, and development of new core technologies for structural and functional genomics. A new methods have been described for protein cyclization using inteins and for in vitro preparative protein synthesis and labelling.
Facilities for study of protein structure and function. Expression of proteins in bacteria, protein purification, characterization by mass spectrometry, high-field NMR, protein X-ray crystallography, SPR analysis by BIACORE.
National Center for Biotechnology (CNB), madrid, SPAIN