Cloning-independent expression and analysis of omega-transaminases by use of a cell-free protein synthesis system

Herewith we report the expression and screening of microbial enzymes without involving cloning procedures. Computationally predicted putative omega-transaminase (omega-TA) genes were PCR amplified from the bacterial colonies and expressed in a cell-free protein synthesis system for subsequent analysis of their enzymatic activity and substrate specificity. Through the cell-free expression analysis of the putative omega-TA genes, a number of enzyme-substrate pairs were identified in a matter of hours. We expect that the proposed strategy will provide a universal platform for bridging the information gap between nucleotide sequence and protein function to accelerate the discovery of novel enzymes.