Abstract:  Proteins transport electrons intramolecularly and across the cell using bound metal/organic groups held in precise spatial arrangements.  Many are massive molecular 'nano-machines' that do chemistry critical to life on our planet from photosynthesis to nitrogen fixation.  If we can understand how such complex extant proteins arose from simpler forms, it would give us insights into the origins of life, and allow engineering of synthetic proteins that could be used as organometallic devices - transistors, circuits, etc.
The discussion will center around two short stories. 

First - a dissection of a single metalloprotein to identify the structural quintessence required for electron transfer. 

Second - a comprehensive analysis of the atomic-resolution structures of metalloproteins in the Protein Data Bank to determine patterns of connectivity between these minimal elements.  These two levels of study have produced a bipartite network that is presumably rich in information about evolutionary and functional relationships.  We look forward to a discussion of what mathematical tools and approaches could be used to probe this complex network.