The KlPMR1 gene of Kluyveromyces lactis encodes for a P-type Ca2+-ATPase

A novel P-type Ca2+-ATPase gene has been cloned and sequenced in the yeast Kluyveromyces lactis. The gene has been named KlPIMR1 and is localized on c hromosome I. The putative gene product contains 936 residues and has a calc ulated molecular weight of 102 437 Da. Analysis of the deduced amino acid s equence (KlPmrlp) indicated that the encoded protein retains all the highly conserved domains characterizing the P-type ATPases. KlPmr1p shares 71% am ino acid identity with Pmr1p of S. cerevisiae, 62% with HpPmr1p of Hansenul a polymorpha, 56% with YlPmr1p of Yarrowia lipolytica and 52% with the Ca2-ATPase encoded for by the SPCAI gene of Rattus norvegicus; these similarit ies place KlPmr1p in the SPCA group (secretory pathway Ca2+-ATPase) of the P-type ATPases. The ii: lactis strain harbouring the Klpmr1 disrupted gene is not able to grow in presence of low calcium concentrations and shows hyp ersensitivity to high concentrations of EGTA in the medium. These defects a re relieved by PMR1 of S, cerevisiae on a centromeric plasmid, demonstratin g that KlPMR1 encodes for a functional Pmr1p homologue. The sequence descri bed can be retrieved under EMBL Accession No. AJ001018. Copyright (C) 1999 John WiIey & Sons, Ltd.