| abstract |
The present invention provides compositions and methods for producing a heterologous protein of interest by inserting a copy of a gene encoding the heterologous protein of interest into the chromosome of a host cell, such as E. coli. A chromosomal transfer DNA (a circular, non-self-replicating DNA) is used to integrate the gene encoding the heterologous protein of interest into the host cell chromosome. The chromosomal transfer DNA comprises at least one selectable marker and may optionally include repeated DNA sequences flanking the selectable marker, facilitating chromosomal amplification of the integrated DNA. The gene encoding the protein of interest may be expressed after integration into the chromosome of the host cell; selection for chromosomal amplification may be performed prior to expression of the gene. |