Construction and expression of a synthetic wheat storage protein gene

Abstract

A synthetic wheat high-molecular-weight (HMW) glutenin storage protein gene analog was constructed for expression in E. coli. This first synthetic HMW-glutenin gene and future modifications are intended to allow systematic dissection of the molecular basis of HMW-glutenin role in the visco-elastic properties critical for wheat product processing and utilization. The design of the included four features: different construction strategies for the separate assembly of major polypeptide domains, the inclusion of convenient restriction sites for modifications, use of a codon selection similar to E. coli highly expressed genes, and the ability to produce repetitive sequence domains of exact numbers of defined repeats. The complete synthetic HMW-glutenin construct was 1908 bp, and contained 32 identical copies of one of the HMW-glutenin repetitive domain motifs. The gene expressed the novel HMW-glutenin protein to relatively high levels in bacterial cultures and the protein exhibited the known anomalous behavior of HMW-glutenins in SDS-PAGE.