title: Exploration of yeast alkali metal cation/H+ antiporters: sequence and structure comparison.
abstract: The Saccharomyces cerevisiae genome contains three genes encoding alkali metal cation/H+ antiporters (Nha1p, Nhx1p, Kha1p) that differ in cell localization, substrate specificity and physiological function. Systematic genome sequencing of other yeast species revealed highly conserved homologous ORFs in all of them. We compared the yeast sequences both at DNA and protein levels. The subfamily of yeast endosomal/prevacuolar Nhx1 antiporters is closely related to mammalian plasma membrane NHE proteins and to both plasma membrane and vacuolar plant antiporters. The high sequence conservation within this subfamily of yeast antiporters suggests that Nhx1p is of great importance in cell physiology. Yeast Kha1 proteins probably belong to the same subfamily as bacterial antiporters, whereas Nhal proteins form a distinct subfamily.
authors.affiliation: Department of Membrane Transport, Institute of Physiology, Academy of Sciences of the Czech Republic, 142 20 Prague, Czechia.
authors.forename: L
authors.initials: L
authors.lastname: Pribylová
authors.forename: K
authors.initials: K
authors.lastname: Papousková
authors.forename: M
authors.initials: M
authors.lastname: Zavrel
authors.forename: J L
authors.initials: JL
authors.lastname: Souciet
authors.forename: H
authors.initials: H
authors.lastname: Sychrová
mesh_terms: D000595:Amino Acid Sequence; D027682:Cation Transport Proteins / Q000737:chemistry* / Q000145:classification / Q000235:genetics; D004271:DNA, Fungal / Q000032:analysis; D008565:Membrane Proteins / Q000737:chemistry* / Q000145:classification / Q000235:genetics; D008969:Molecular Sequence Data; D010802:Phylogeny; D027961:Potassium-Hydrogen Antiporters / Q000737:chemistry* / Q000145:classification / Q000235:genetics; D029701:Saccharomyces cerevisiae Proteins / Q000737:chemistry* / Q000145:classification / Q000235:genetics; D017422:Sequence Analysis, DNA; D017386:Sequence Homology, Amino Acid; D017923:Sodium-Hydrogen Exchangers / Q000737:chemistry* / Q000145:classification / Q000235:genetics
chemical_list: D027682:Cation Transport Proteins; D004271:DNA, Fungal; C421963:KHA1 protein, S cerevisiae; D008565:Membrane Proteins; C000631624:NHA1 protein, S cerevisiae; C492183:NHX1 protein, S cerevisiae; D027961:Potassium-Hydrogen Antiporters; D029701:Saccharomyces cerevisiae Proteins; D017923:Sodium-Hydrogen Exchangers