ABCB1 p.Tyr950Cys
| Predicted by SNAP2: | A: D (75%), C: D (59%), D: D (85%), E: D (91%), F: N (72%), G: D (80%), H: D (75%), I: D (75%), K: D (91%), L: D (75%), M: D (59%), N: D (80%), P: D (91%), Q: D (80%), R: D (91%), S: D (80%), T: D (80%), V: D (71%), W: D (85%), |
| Predicted by PROVEAN: | A: D, C: D, D: D, E: D, F: N, G: D, H: D, I: D, K: D, L: D, M: D, N: D, P: D, Q: D, R: D, S: D, T: D, V: D, W: D, |
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[hide] Insight in eukaryotic ABC transporter function by ... FEBS Lett. 2006 Feb 13;580(4):1064-84. Epub 2006 Jan 19. Frelet A, Klein M
Insight in eukaryotic ABC transporter function by mutation analysis.
FEBS Lett. 2006 Feb 13;580(4):1064-84. Epub 2006 Jan 19., 2006-02-13 [PMID:16442101]
Abstract [show]
With regard to structure-function relations of ATP-binding cassette (ABC) transporters several intriguing questions are in the spotlight of active research: Why do functional ABC transporters possess two ATP binding and hydrolysis domains together with two ABC signatures and to what extent are the individual nucleotide-binding domains independent or interacting? Where is the substrate-binding site and how is ATP hydrolysis functionally coupled to the transport process itself? Although much progress has been made in the elucidation of the three-dimensional structures of ABC transporters in the last years by several crystallographic studies including novel models for the nucleotide hydrolysis and translocation catalysis, site-directed mutagenesis as well as the identification of natural mutations is still a major tool to evaluate effects of individual amino acids on the overall function of ABC transporters. Apart from alterations in characteristic sequence such as Walker A, Walker B and the ABC signature other parts of ABC proteins were subject to detailed mutagenesis studies including the substrate-binding site or the regulatory domain of CFTR. In this review, we will give a detailed overview of the mutation analysis reported for selected ABC transporters of the ABCB and ABCC subfamilies, namely HsCFTR/ABCC7, HsSUR/ABCC8,9, HsMRP1/ABCC1, HsMRP2/ABCC2, ScYCF1 and P-glycoprotein (Pgp)/MDR1/ABCB1 and their effects on the function of each protein.
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No. Sentence Comment
516 ATP hydrolysis promoted the interaction between the extracellular ends of TM1 and TM11 as shown by mutating M68 and M69 (TM1) and Y950C, Y953, A954, F957 (TM11) into cysteines followed by cross-linking experiments of different combinations of these mutants [255].
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ABCB1 p.Tyr950Cys 16442101:516:130
status: NEW[hide] ATP hydrolysis promotes interactions between the e... Biochemistry. 2005 Aug 2;44(30):10250-8. Loo TW, Bartlett MC, Clarke DM
ATP hydrolysis promotes interactions between the extracellular ends of transmembrane segments 1 and 11 of human multidrug resistance P-glycoprotein.
Biochemistry. 2005 Aug 2;44(30):10250-8., 2005-08-02 [PMID:16042402]
Abstract [show]
P-glycoprotein (P-gp, ABCB1) actively pumps a broad range of structurally unrelated cytotoxic compounds out of the cell. It has two homologous halves that are joined by a linker region. Each half has a transmembrane (TM) domain containing six TM segments and a nucleotide-binding domain (NBD). Cross-linking studies have shown that the drug-binding pocket is at the interface between the TM domains. The two NBDs interact to form the ATP-binding sites. Coupling of ATP hydrolysis to drug efflux has been postulated to occur by conversion of the binding pocket from a high-affinity to a low-affinity state through alterations in the packing of the TM segments. TM 11 has also been reported to be important for drug binding. Here, we used cysteine-scanning mutagenesis and oxidative cross-linking to test for changes in the packing of TM 11 during ATP hydrolysis. We generated 350 double cysteine mutants that contained one cysteine at the extracellular end of TM11 and another cysteine at the extracellular ends of TMs 1, 3, 4, 5, or 6. The mutants were expressed in HEK293 cells and treated with oxidant in the absence or presence of ATP. Cross-linked product was not detected in SDS-PAGE gels in the absence of ATP. By contrast, cross-linked product was detected in mutants M68C(TM1)/Y950C(TM11), M68C(TM1)/Y953C(TM11), M68C(TM1)/A954C(TM11), M69C(TM1)/A954C(TM11), and M69C(TM1)/ F957C(TM11) in the presence of ATP but not with ADP or AMP.PNP. These results indicate that rearrangement of TM11 may contribute to the release of drug substrate during ATP hydrolysis.
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No. Sentence Comment
158 Finally, we tested whether mutants M68C(TM1)/Y950C- (TM11), M68C(TM1)/Y953C(TM11), M68C(TM1)/A954C- (TM11), M69C(TM1)/A954C(TM11), and M69C(TM1)/ F957C(TM11) that showed ATP-dependent cross-linking were still active.
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ABCB1 p.Tyr950Cys 16042402:158:45
status: NEW