ABCMdb

ABCC7 p.Ala238Asp

ClinVar:	c.713C>T , p.Ala238Val ? , not provided
CF databases:	c.713C>T , p.Ala238Val (CFTR1) ? , A new mutation was found (by DHPLC, then both strands DNA have been sequenced) in a CBAVD patient from Southern Italy.
Predicted by SNAP2:	C: D (63%), D: D (85%), E: D (66%), F: D (85%), G: N (72%), H: D (85%), I: D (75%), K: D (66%), L: D (63%), M: D (71%), N: D (75%), P: D (71%), Q: D (75%), R: D (63%), S: N (78%), T: N (72%), V: D (71%), W: D (91%), Y: D (85%),
Predicted by PROVEAN:	C: N, D: D, E: N, F: D, G: N, H: D, I: D, K: N, L: D, M: D, N: N, P: D, Q: N, R: N, S: N, T: N, V: D, W: D, Y: D,

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Publications
[hide] Non-native interhelical hydrogen bonds in the cyst... Biochemistry. 2004 Jun 29;43(25):8077-83. Choi MY, Cardarelli L, Therien AG, Deber CM
Non-native interhelical hydrogen bonds in the cystic fibrosis transmembrane conductance regulator domain modulated by polar mutations.
Biochemistry. 2004 Jun 29;43(25):8077-83., [PMID:15209503]

Abstract [show]
Polar residues comprise about 15% of the transmembrane (TM) domains of proteins, where they can stabilize structure via native side chain-side chain interhelical hydrogen bonds between TM helices. However, non-native H-bonds may be implicated in disease states, through limiting protein dynamics during transport and/or misfolding the protein by inducing non-native rotational positions about TM helical axes. Here we have undertaken an investigation of the presence and strength of H-bond interactions within a series of helix-loop-helix ("hairpin") constructs derived from TM helices 3 and 4 (italic) of the cystic fibrosis transmembrane conductance regulator (CFTR) (prototypic sequence G(194)LALAHFVWIAPLQ(207)VALLMGLIWELLQASAFAGLGFLIV(232)LALFQ(237)AGLG(241)) in which wild-type Q207 in TM3 forms an interhelical H-bond with CF-phenotypic mutant V232D in TM4 [Therien, A. G., Grant, F. E., and Deber, C. M. (2001) Nat. Struct. Biol 8, 597-601]. In the present work, a library of 21 TM3/4 constructs was prepared, where Asp residues were placed individually at TM4 positions 221-241. Using gel shift assays-in which H-bond-linked hairpins (closed conformation) migrate faster than the elongated forms (open conformation)-we found that Q207 in TM3 is able to "capture" all 21 TM4 D mutations into measurable populations of interhelical H-bonds. A similar library of TM4 D mutants-but also containing Q207L-reverted to wild-type migration rates, confirming Q207 as the polar partner for TM4 D residues. In view of the broad capture range of Q207, these results emphasize the potential consequences to folding and dynamics of introducing polar mutations into the TM domains of membrane proteins in the vicinity of a native polar TM residue.

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119 Our results indicate a discrete role for Q237, viz., the double mutants F224D/ Q237L, A238D/Q237L and G239D/Q237Lsin which the D locus is nearer to the Nor C-terminus of the TM4 helixs returned to the wt migration rate. Login to comment
178 From the results (Figures 5 and 7), we found that double mutants where D is relatively distant from Q207 in TM3 (F224D/ Q237L, A238D/Q237L, and G239D/Q237L) returned to the wt migration rate, whereas the other double mutants (V232D/ Q237L and L230D/Q237L) migrated more slowly than the corresponding D mutants, but still significantly faster than the wt construct. Login to comment
188 Nevertheless, for any A f D or G f D mutants (in this case, A221D, A223D, G226D, G228D, A234D, A238D, G239D, and G241D), only a single-base change is required, and therefore, it is possible these mutants represent potential phenotypic CF mutants, which have yet to be discovered. Login to comment