Dr. Terry Hwa
Distinguished Professor, UCSD, Department of Molecular Biology
Faculty Profile

Distantly related bacteria share a rigid proteome allocation strategy with flexible enzyme kinetics

Tuesday, April 22
11:30 AM
AHF 153 (Torrey Webb Room)

Abstract: Bacteria are known to allocate their proteomes according to how fast they grow, and the allocation strategies employed strongly affect bacterial adaptation to different environments. Much of what is currently known about proteome allocation is based on extensive studies of the model organism E. coli. It is not clear how much of E. coli’s proteome allocation strategy is applicable to other species, particularly since different species can grow at vastly different rates even in the same growth condition. In this study we compare proteome allocation programs quantitatively between several distantly-related bacterial species, including V. natriegens, one of the fastest-growing bacteria known. Extensive characterization across conditions reveals an invariant allocation program in response to different nutrients despite systemic, species-specific differences in enzyme kinetics. This invariant program is not organized according to the growth rate but is based on a common internal metric of nutrient quality, with the faster species behaving as if it is growing under a higher temperature. The flexibility of enzyme kinetics across species and the rigidity of enzyme abundance across nutrient conditions defy common notions of evolvability and resource optimization. They suggest the existence of blueprint(s) of proteome allocation shared by diverse bacterial species organized independently of phylogeny.