Journal article
Restoring Global Gene Regulation through Experimental Evolution Uncovers a NAP (Nucleoid-Associated Protein)-Like Behavior of Crp/Cap
Novo Nordisk Foundation Center for Biosustainability, Technical University of Denmark1
Genome Engineering, Novo Nordisk Foundation Center for Biosustainability, Technical University of Denmark2
Microbial Evolution and Synthetic Biology, Research Groups, Novo Nordisk Foundation Center for Biosustainability, Technical University of Denmark3
How do hierarchical gene regulation networks evolve in bacteria? Nucleoid-associated proteins (NAPs) influence the overall structure of bacterial genomes, sigma factors and global transcription factors (TFs) control thousands of genes, and many operons are regulated by highly specific TFs that in turn are controlled allosterically by cellular metabolites.
These regulatory hierarchies have been shaped by millions of years of evolution to optimize fitness in response to changing environmental conditions, but it is unclear how NAPs and TFs relate and have evolved together. Cyclic AMP (cAMP) receptor protein (Crp) is the paradigmatic global TF in Escherichia coli, and here we report that mutations in the topA gene compensate for loss of cAMP, showing that the interplay between Crp and the supercoiling status of promoters is key to global stress response.
Furthermore, we observed an effect of apoCrp on gene expression in the absence of its effector cAMP. This provides support for the proposed NAP-like role for Crp, suggesting that it represents an intermediate point in the evolution of a ligand-controlled TF from a NAP. IMPORTANCE Here we report that mutations in the topA gene compensate for loss of cAMP, showing that the interplay between Crp and the supercoiling status of promoters is key to global stress response.
Furthermore, we observed an effect of apoCrp on gene expression in the absence of its effector cAMP. This provides support for the proposed NAP-like role for Crp, suggesting that it represents an intermediate point in the evolution of a ligand-controlled TF from a NAP.
Language: | English |
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Publisher: | American Society for Microbiology |
Year: | 2021 |
Pages: | e0202821 |
ISSN: | 21612129 and 21507511 |
Types: | Journal article |
DOI: | 10.1128/mBio.02028-21 |
ORCIDs: | Heyde, Sophia A H , Nørholm, Morten H H , Frendorf, Pernille O and Lauritsen, Ida |