High level expression of glucose-6-phosphate dehydrogenase gene PsG6PDH from Populus suaveolens in E. coli

In order to investigate the functions of the gene PsG6PDH and the mechanisms underlying freezing tolerance of Populus suaveolens, the recombinant expression vector pET-G (pET30a-G6PDH), which contained full encoding region of PsG6PDH gene, was established. The recombinant was identified by lawn-PCR and double enzyme digestion and then transformed into expression host XA90 and induced by isopropyl-â-D-thiogalactoside (IPTG) to express 100 kD polypeptide of G6PDH fusion protein. The results showed that the expressed amount of the fusion protein culminated after 1 mmol·L−1 IPTG treatment for 4 h and that pET-G product was predominately soluble and not extra-cellular secreting.