striking effects of spacer and terminator sequences on the synthesis of porcine growth hormone in Escherichia coli

Two types of expression vectors containing the P sub(tac) or P sub(L) promoters, synthetic ribosomal-binding sequences (RBS), and a transcriptional terminator (rrnBT sub(1)T sub(2)) were constructed for the production of porcine growth hormone (pGH) in Escherichia coli). The results demonstrated that the nucleotide sequence between the RBS and the start codon, ATG, was critical for the yields of pGH. The rrnBT sub(1)T sub(2)terminator was essential for the efficient expression of pGH in the P sub(tac)-driven vectors, but reduced the synthesis of pGH in the P sub(L)-vectors. A leaky repression was observed in the JM103 cells containing the P sub(tac)-plasmids.