Point mutations in a pBR322-based expression plasmid resulting in increased synthesis of bovine growth hormone in Escherichia coli

Gene. 1990 Feb 14;86(2):137-44. doi: 10.1016/0378-1119(90)90272-s.


The bGH cDNA coding for bovine growth hormone (bGH) is expressed poorly in Escherichia coli using a pBR322-based expression plasmid. Random mutagenesis of the plasmid gave rise to two types of plasmid mutants which increased the expression of bGH. One class had single base changes in the first four codons of the bGH sequence. The second class had single base changes in regions of the plasmid involved in controlling plasmid replication but had little effect on plasmid copy number.

MeSH terms

  • Amino Acid Sequence
  • Animals
  • Base Sequence
  • Cattle
  • Cloning, Molecular / methods
  • DNA / genetics
  • Escherichia coli / genetics*
  • Gene Expression
  • Growth Hormone / genetics*
  • Molecular Sequence Data
  • Mutation*
  • Plasmids*
  • Restriction Mapping


  • Growth Hormone
  • DNA