Big jobs go to loyal proteins
Cells offload nonessential work on multitasking enzymes
http://www.sciencenews.org/view/generic/id/343412/title/Big_jobs_go_to_loyal_proteins
This is an interesting idea to me. I have been steeped in the paradigm of one enzyme – one substrate for a very long time. The idea that some enzymes can provide functionality for multiple types of activities is quite interesting and makes a lot of sense from an evolutionary perspective. That certain enzymes critical to the success of the cell would become highly specialized over evolutionary timescales makes even more sense (anything that gives an organism an edge in survival/reproduction will help it thrive against competition). Indeed, it helps fill in the ‘gap’ in going from non-living to living (a rather arbitrary line that most agree has to do with replication) if we accept that the earlier versions of enzymes were generalists rather than specialists.