6hh0

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Yeast V-ATPase transmembrane helix 7 NMR structure in DPC micellesYeast V-ATPase transmembrane helix 7 NMR structure in DPC micelles

Structural highlights

6hh0 is a 1 chain structure with sequence from Saccharomyces cerevisiae. Full experimental information is available from OCA. For a guided tour on the structure components use FirstGlance.
Method:Solution NMR
Resources:FirstGlance, OCA, PDBe, RCSB, PDBsum, ProSAT

Function

VPP1_YEAST Subunit of the V0 complex of vacuolar(H+)-ATPase (V-ATPase), a multisubunit enzyme composed of a peripheral complex (V1) that hydrolyzes ATP and a membrane integral complex (V0) that translocates protons (PubMed:11278748, PubMed:1491220, PubMed:8798414). V-ATPase is responsible for acidifying and maintaining the pH of intracellular compartments (PubMed:11278748, PubMed:1491220). Is present only in vacuolar V-ATPase complexes; enzymes containing this subunit have a 4-fold higher ratio of proton transport to ATP hydrolysis than complexes containing the Golgi/endosomal isoform and undergo reversible dissociation of V1 and V0 in response to glucose depletion (PubMed:11278748, PubMed:8798414).[1] [2] [3]

Publication Abstract from PubMed

Vacuolar ATPases are multisubunit protein complexes that are indispensable for acidification and pH homeostasis in a variety of physiological processes in all eukaryotic cells. An arginine residue (Arg-735) in transmembrane helix 7 (TM7) of subunit a of the yeast ATPase is known to be essential for proton translocation. However, the specific mechanism of its involvement in proton transport remains to be determined. Arginine residues are usually assumed to "snorkel" toward the protein surface when exposed to a hydrophobic environment. Here, using solution NMR spectroscopy, molecular dynamics simulations and in vivo yeast assays, we obtained evidence for the formation of a transient, membrane-embedded cation-pi interaction in TM7 between Arg-735 and two highly conserved nearby aromatic residues, Tyr-733 and Trp-737. We propose a mechanism by which the transient, membrane-embedded cation-pi complex provides the necessary energy to keep the charged side chain of Arg-735 within the hydrophobic membrane. Such cation-pi interactions may define a general mechanism to retain charged amino acids in a hydrophobic membrane environment.

A cation-pi interaction in a transmembrane helix of vacuolar ATPase retains the proton transporting arginine in a hydrophobic environment.,Hohlweg W, Wagner GE, Hofbauer HF, Sarkleti F, Setz M, Gubensak N, Lichtenegger S, Falsone SF, Wolinski H, Kosol S, Oostenbrink C, Kohlwein SD, Zangger K J Biol Chem. 2018 Sep 12. pii: RA118.005276. doi: 10.1074/jbc.RA118.005276. PMID:30209131[4]

From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine.

See Also

References

  1. Kawasaki-Nishi S, Nishi T, Forgac M. Yeast V-ATPase complexes containing different isoforms of the 100-kDa a-subunit differ in coupling efficiency and in vivo dissociation. J Biol Chem. 2001 May 25;276(21):17941-8. Epub 2001 Mar 2. PMID:11278748 doi:http://dx.doi.org/10.1074/jbc.M010790200
  2. Manolson MF, Proteau D, Jones EW. Evidence for a conserved 95-120 kDa subunit associated with and essential for activity of V-ATPases. J Exp Biol. 1992 Nov;172:105-12. PMID:1491220
  3. Leng XH, Manolson MF, Liu Q, Forgac M. Site-directed mutagenesis of the 100-kDa subunit (Vph1p) of the yeast vacuolar (H+)-ATPase. J Biol Chem. 1996 Sep 13;271(37):22487-93. PMID:8798414
  4. Hohlweg W, Wagner GE, Hofbauer HF, Sarkleti F, Setz M, Gubensak N, Lichtenegger S, Falsone SF, Wolinski H, Kosol S, Oostenbrink C, Kohlwein SD, Zangger K. A cation-pi interaction in a transmembrane helix of vacuolar ATPase retains the proton transporting arginine in a hydrophobic environment. J Biol Chem. 2018 Sep 12. pii: RA118.005276. doi: 10.1074/jbc.RA118.005276. PMID:30209131 doi:http://dx.doi.org/10.1074/jbc.RA118.005276
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