title: A protein constructed de novo enables cell growth by altering gene regulation.
abstract: Recent advances in protein design rely on rational and computational approaches to create novel sequences that fold and function. In contrast, natural systems selected functional proteins without any design a priori. In an attempt to mimic nature, we used large libraries of novel sequences and selected for functional proteins that rescue Escherichia coli cells in which a conditionally essential gene has been deleted. In this way, the de novo protein SynSerB3 was selected as a rescuer of cells in which serB, which encodes phosphoserine phosphatase, an enzyme essential for serine biosynthesis, was deleted. However, SynSerB3 does not rescue the deleted activity by catalyzing hydrolysis of phosphoserine. Instead, SynSerB3 up-regulates hisB, a gene encoding histidinol phosphate phosphatase. This endogenous E. coli phosphatase has promiscuous activity that, when overexpressed, compensates for the deletion of phosphoserine phosphatase. Thus, the de novo protein SynSerB3 rescues the deletion of serB by altering the natural regulation of the His operon.
authors.affiliation: Department of Chemistry, Princeton University, Princeton, NJ 08540.
authors.forename: Katherine M
authors.initials: KM
authors.lastname: Digianantonio
authors.affiliation: Department of Chemistry, Princeton University, Princeton, NJ 08540 hecht@princeton.edu.
authors.forename: Michael H
authors.initials: MH
authors.lastname: Hecht
mesh_terms: D055162:Biocatalysis; D003470:Culture Media; D004926:Escherichia coli / Q000201:enzymology / Q000254:growth & development; D029968:Escherichia coli Proteins / Q000737:chemistry* / Q000378:metabolism / Q000502:physiology; D020869:Gene Expression Profiling; D006868:Hydrolysis; D009876:Operon; D010744:Phosphoric Monoester Hydrolases / Q000737:chemistry / Q000235:genetics / Q000378:metabolism; D013014:SOS Response, Genetics; D014158:Transcription, Genetic
chemical_list: D003470:Culture Media; D029968:Escherichia coli Proteins; D010744:Phosphoric Monoester Hydrolases; C022394:phosphoserine phosphatase
keywords: auxotroph; de novo protein design; hisB; serB; synthetic biology