This work is in progress, based on pET21a inserting between NdeI and NotI sites.
The protocol being used is essentially as in Elledge, 2007, with RecA.
See supplementary protcol #2 file - via CNRS Direct Nature URL from
Li M.Z. & Elledge S. J. Harnessing homologous recombination in vitro to generate recombinant DNA via SLIC. Nature Methods 4, 251 - 256 (2007) doi:10.1038/nmeth1010