ABCC7 p.Arg487Ser
| Predicted by SNAP2: | A: D (91%), C: D (95%), D: D (95%), E: D (95%), F: D (95%), G: D (95%), H: D (91%), I: D (95%), K: D (75%), L: D (95%), M: D (95%), N: D (95%), P: D (95%), Q: D (85%), S: D (95%), T: D (95%), V: D (91%), W: D (95%), Y: D (95%), |
| Predicted by PROVEAN: | A: N, C: D, D: N, E: N, F: D, G: N, H: N, I: D, K: N, L: D, M: N, N: N, P: D, Q: N, S: N, T: N, V: D, W: D, Y: D, |
[switch to compact view]
Comments [show]
None has been submitted yet.
[hide] Deletion of Phenylalanine 508 in the First Nucleot... J Biol Chem. 2015 Sep 18;290(38):22862-78. doi: 10.1074/jbc.M115.641134. Epub 2015 Jul 6. Chong PA, Farber PJ, Vernon RM, Hudson RP, Mittermaier AK, Forman-Kay JD
Deletion of Phenylalanine 508 in the First Nucleotide-binding Domain of the Cystic Fibrosis Transmembrane Conductance Regulator Increases Conformational Exchange and Inhibits Dimerization.
J Biol Chem. 2015 Sep 18;290(38):22862-78. doi: 10.1074/jbc.M115.641134. Epub 2015 Jul 6., [PMID:26149808]
Abstract [show]
Deletion of Phe-508 (F508del) in the first nucleotide-binding domain (NBD1) of the cystic fibrosis transmembrane conductance regulator (CFTR) results in destabilization of the domain, intramolecular interactions involving the domain, and the entire channel. The destabilization caused by F508del manifests itself in defective channel processing and channel gating defects. Here, we present NMR studies of the effect of F508del and the I539T stabilizing mutation on NBD1 dynamics, with a view to understanding these changes in stability. Qualitatively, F508del NMR spectra exhibit significantly more peak broadening than WT spectra due to the enhanced intermediate time scale (millisecond to microsecond) motions in the mutant. Unexpectedly, studies of fast (nanosecond to picosecond) motions revealed that F508del NBD1 tumbles more rapidly in solution than WT NBD1. Whereas F508del tumbles at a rate nearly consistent with the monomeric state, the WT protein tumbles significantly more slowly. Paramagnetic relaxation enhancement experiments confirm that NBD1 homodimerizes in solution in the expected head-to-tail orientation. NMR spectra of WT NBD1 reveal significant concentration-dependent chemical shift perturbations consistent with NBD1 dimerization. Chemical shift analysis suggests that the more rapid tumbling of F508del is the result of an impaired ability to dimerize. Based on previously published crystal structures and NMR spectra of various NBD1 mutants, we propose that deletion of Phe-508 affects Q-loop conformational sampling in a manner that inhibits dimerization. These results provide a potential mechanism for inhibition of channel opening by F508del and support the dimer interface as a target for cystic fibrosis therapeutics.
Comments [show]
None has been submitted yet.
No. Sentence Comment
244 To determine whether we were observing intermolecular interactions between Arg-487 and Asp-565 and Asp-567, which form the di-acidic motif, we introduced the R487S mutation to remove the positive charge and disrupt this interface.
X
ABCC7 p.Arg487Ser 26149808:244:158
status: NEW245 R487S NBD1 èc;RIèc;RE still exhibits FIGURE 7. a, mapping of the concentration-dependent chemical shift perturbations for NBD1 on a ribbon diagram of NBD1 using spheres colored according to the legend.
X
ABCC7 p.Arg487Ser 26149808:245:0
status: NEW