tokens: However , the N63S mutation in the wild-type VP5 background increased the interaction , as judged by the beta-galactosidase activity , by a factor of 9 relative to when the PR7 mutation was present .
folded_tokens: however , the n63 mutation in the wild-type vp5 background increase the interaction , as judge by the beta-galactosidase activity , by a factor of 9 relative to when the pr7 mutation be present .