[Cloning the gene for vaccinia virus strain L-IVP growth factor in Escherichia coli]

The growth factor gene of the vaccinia virus LIVP strain has been primarily cloned in a 4.3 kbp long BamHI-EcoRI fragment and then subcloned in a 440 bp fragment. It was shown that clone 4 of the LIVP strain contains a single copy of this gene while the WR strain contains a repeat. The gene is located on a 4.3 kbp BamHI-EcoRI fragment but not on a 2.2 kbp fragment and has four nucleotide changes, three of which result in amino acid substitutions.