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Probing the Mechanism by which Proteins Designed De Novo Function in Living Cells
Author(s) -
Digianantonio Katie,
Hecht Michael
Publication year - 2015
Publication title -
the faseb journal
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.709
H-Index - 277
eISSN - 1530-6860
pISSN - 0892-6638
DOI - 10.1096/fasebj.29.1_supplement.891.9
Subject(s) - biology , proteome , phosphoserine , serine , function (biology) , synthetic biology , transcriptome , biochemistry , protein phosphatase 2 , phosphatase , microbiology and biotechnology , gene , computational biology , gene expression , enzyme
One goal of synthetic biology is the design of a collection of novel proteins to create an artificial proteome. The Hecht lab made initial progress toward this goal by producing a library of stable novel proteins that are not similar to any naturally occurring proteins, but nonetheless function in vivo . The E. coli strain Δ serB , which cannot grow on minimal media due to the chromosomal deletion of phosphoserine phosphatase (which is essential for the biosynthesis of serine), was transformed with a library of de novo designed proteins and screened for growth. Four novel proteins, named SynSerB1, 2, 3, and 4, were found to rescue this strain on minimal media. Since the pure SynSerB proteins do not perform the reaction that wild‐type SerB performs in the cell, we suspect that the SynSerB proteins may function by altering the expression of an endogenous protein. Assaying the transcriptome of cells expressing SynSerB3 revealed an overexpression of the histidine operon, including HisB, a phosphatase that can utilize phosphoserine as a substrate. These experiments indicate that the de novo designed proteins rescue the auxotroph by upregulating an endogenous protein thereby providing an alternative way to synthesize serine. This study demonstrates that proteins designed de novo can function in vivo and sustain cell growth by altering the regulation of natural genes. This study was funded by the NSF through the Graduate Research Fellowship Program and by grants MCB‐1050510 and MCB‐1409402