Saccharomyces cerevisiae IMX2538
Saccharomyces cerevisiae, whose evolutionary past includes a whole-genome duplication event, is characterised by a mosaic genome configuration with substantial apparent genetic redundancy. This apparent redundancy raises questions about the evolutionary driving force for genomic fixation of minor paralogs and complicates modular and combinatorial metabolic engineering strategies. While isoenzymes might be important in specific environments, they could be dispensable in controlled laboratory or industrial contexts. The present study explores the extent to which the genetic complexity of the central carbon metabolism (CCM) in S. cerevisiae, here defined as the combination of glycolysis, pentose phosphate pathway, tricarboxylic acid cycle and a limited number of related pathways and reactions, can be reduced by elimination of (iso)enzymes without major negative impacts on strain physiology. Cas9-mediated, groupwise deletion of 35 from the 111 genes yielded a minimal CCM strain, which despite the elimination of 32 percent of CCM-related proteins, showed only a minimal change in phenotype on glucose-containing synthetic medium in controlled bioreactor cultures relative to a congenic reference strain. Analysis under a wide range of other growth and stress conditions revealed remarkably few phenotypic changes of the reduction of genetic complexity. Still, a well-document context-dependent role of GPD1 in osmotolerance was confirmed. The minimal CCM strain provides a model system for further research into genetic redundancy of yeast genes and a platform for strategies aimed at large-scale, combinatorial remodelling of yeast CCM.
strain
IMX2538
host
Saccharomyces cerevisiae CEN.PK102-12A
collection_date
2020
geo_loc_name
Netherlands
sample_type
genetically engineered
biomaterial_provider
Pascale Daran-Lapujade
genotype
MATa ura3-52 his3-1 leu2-3,112 MAL2-8c SUC2 glk1delta::Sphis5 hxk1delta::KlLEU2 tdh1delta tdh2delta gpm2delta gpm3delta eno1delta pyk2delta pdc5delta pdc6delta adh2delta adh5delta adh4delta can1delta::cas9-natNT2 gnd2delta tkl2delta sol4delta nqm1delta pyc2delta sdh1bdelta shh3delta shh4delta cit3delta aac1delta aac3delta sal1delta mpc3delta ctp1delta odc1DELTA ndt2delta frds1delta idp1delta idp2delta ald3delta gpd1delta gpp2delta::URA3
BioSampleModel
Microbe, viral or environmental