A strategy simplifying site-directed mutagenesis in the CD4-binding region of HIV gp 120

Abstract
By site-directed mutagenesis, two unique restriction sites, surrounding the CD4-binding DNA region of HIV gp 120, were created. The mutations do not cause amino acid substitutions but generate a DNA fragment, which is stable when cloned into M13 for further mutagenesis and is also easy to reclone.