tokens: Collectively , these experiments demonstrate that CFTR 's NBF1+ R region and its NBF2 domain , after folding separately as distinct units , have a strong propensity to interact and that this interaction is stable in the absence of added nucleotides or exogenously induced phosphorylation .
folded_tokens: collectively , these experiment demonstrate that CFTR 's nbf1+ r region and its nbf2 domain , after folding separately as distinct unit , have a strong propensity to interact and that this interaction be stable in the absence of add nucleotide or exogenously induce phosphorylation .