Cloning and Expression of Methionine-enriched Glycinin GY4-Genes in E. Coli

Abstract

Cloned cDNAs encoding glycinin subunit GY4 was modified to increase methionine content. The effect of the modification was evaluated using an in vitro transcription / translation system. The modifications were carried out in the acidic region; the region which tolerates conservative point mutations. Three bacterial mutants that contain increased amounts of methionine were constructed. These mutants named pSP65/248 Metl, pSP65/248 Met2,3 and pSP65/248 Metl.2,3. Their ability to assemble into oligomer similar to those that occur in the seed, were tested. By putting these modified genes into soybean lines that lack certain glycinin subunits considerable improvements in seed quality can be made.