Increased Expression in Escherichia coli of Human Tumor Necrosis Factor through in Vitro Mutagenesis around the Initiation Codon

Abstract

This study was done to investigate the effects of modified nucleotide sequences around the initiation codon on gene expression efficiency in Escherichia coli. A human tumor necrosis factor-β-galactosidase fused gene was used to randomly modify both the upstream nucleotide sequence from the initiation codon (— 4 to — 1) and the silent third letter of the codons corresponding to the 4 amino acid residues of the N-terminal region. It was observed that the frequency of adenine nucleotide usage in this region was higher in the high expression group than in the low expression group.