Complex sentence: In both of these models DNA duplexes are situated outside of the protein complex, and large movement of protein are needed to achieve the strand exchange, both of which are in stark contrast to the mechanism employed by the tyrosine recombinases.
Split into simpler sentences: In both of these models DNA duplexes are situated outside of the protein complex, and large movement of protein is needed to achieve the strand exchange. This is in stark contrast to the mechanism employed by the tyrosine recombinases.