Three yeast genes, <i>PIR1</i>, <i>PIR2</i> and <i>PIR3</i>, containing internal tandem repeats, are related to each other, and <i>PIR1</i> and <i>PIR2</i> are required for tolerance to heat shock
Description
<jats:title>Abstract</jats:title><jats:p>We isolated three highly homologous genes, <jats:italic>PIR1, PIR2</jats:italic> and <jats:italic>PIR3</jats:italic>, collectively called the <jats:italic>PIR</jats:italic> genes. The remarkable feature of their putative amino acid sequence is that they contain a sequence consisting of 18–19 amino acid residues repeated tandemly seven to ten times. Genes homologous to <jats:italic>PIR</jats:italic> were found in <jats:italic>Kluyveromyces lactis</jats:italic> and <jats:italic>Zygosaccharomyces rouxii</jats:italic> but not in <jats:italic>Schizosaccharomyces pombe</jats:italic>, suggesting that a set of <jats:italic>PIR</jats:italic> genes plays some role in budding yeast. Bias of codon usage seen in each of the <jats:italic>PIR</jats:italic> translation products suggests that they are expressed abundantly. The fact that disruption of each gene is viable indicates that none of them is essential. The double disruptants, <jats:italic>pir1 pir2</jats:italic>, were viable under various conditions, such as higher temperature (37°C) or high salt concentration, but showed a slow‐growing phenotype on an agar slab. Furthermore, they were sensitive to heat shock. Addition of a <jats:italic>pir3</jats:italic> disruption to the <jats:italic>pir1 pir2</jats:italic> double disruptant brought about no phenotypic difference from the original double mutant. <jats:italic>PIR1</jats:italic> and <jats:italic>PIR3</jats:italic> are closely linked to each other and are on chromosome XI.</jats:p>
Journal
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- Yeast
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Yeast 9 (5), 481-494, 1993-05
Wiley
