Protein allocation and utilization in the versatile chemolithoautotroph Cupriavidus necator

eLife

Andreas Hober¹  Alexander Mattausch¹  Markus Janasch¹  Johannes Asplund-Samuelsson¹  Björn Forsström¹  Elton Paul Hudson¹  Michael Jahn¹  Qi Chen¹  Nick Crang¹  Kyle Kimler¹ 

[1] School of Engineering Sciences in Chemistry, Biotechnology and Health, Science for Life Laboratory, KTH – Royal Institute of Technology, Stockholm, Sweden;

关键词: Cupriavidus necator;    Ralstonia eutropha;    resource balance analysis;    substrate limitation;    co2 fixation;    gene fitness;    Other;   

DOI  :  10.7554/eLife.69019

来源: eLife Sciences Publications, Ltd

【 摘 要 】

Bacteria must balance the different needs for substrate assimilation, growth functions, and resilience in order to thrive in their environment. Of all cellular macromolecules, the bacterial proteome is by far the most important resource and its size is limited. Here, we investigated how the highly versatile 'knallgas' bacterium Cupriavidus necator reallocates protein resources when grown on different limiting substrates and with different growth rates. We determined protein quantity by mass spectrometry and estimated enzyme utilization by resource balance analysis modeling. We found that C. necator invests a large fraction of its proteome in functions that are hardly utilized. Of the enzymes that are utilized, many are present in excess abundance. One prominent example is the strong expression of CBB cycle genes such as Rubisco during growth on fructose. Modeling and mutant competition experiments suggest that CO2-reassimilation through Rubisco does not provide a fitness benefit for heterotrophic growth, but is rather an investment in readiness for autotrophy.

【 授权许可】

CC BY