A method of generating a double stranded (ds) recombinant nucleic acid molecule
covalently linked in both strands by contacting two or more ds nucleotide sequences
with a topoisomerase under conditions such that both termini of at least one end
of a first ds nucleotide sequence are covalently linked by the topoisomerase to
both termini of at least one end of a second ds nucleotide sequence is provided.
Also provided is a method for generating a ds recombinant nucleic acid molecule
covalently linked in one strand, by contacting two or more ds nucleotide sequences
with a type IA topoisomerase under conditions such that one strand, but not both
strands, of one or both ends of a first ds nucleotide sequence are covalently linked
by the topoisomerase. Compositions for performing such methods, and compositions
generated from such methods also are provided, as are kits containing components
useful for conveniently practicing the methods.