A PHOSPHATE-REPRESSIBLE, HIGH-AFFINITY PHOSPHATE PERMEASE IS ENCODED BY THE PHO-5(+) GENE OF NEUROSPORA-CRASSA

The pho-5(+) gene of Neurospora crassa, which encodes a high-affinity phosphate permease, has been cloned and analyzed. The deduced ORF of 1707 nucleotides is interrupted by a single 63-nt intron and codes for a protein of 569 amino acids (aa). This aa sequence has 48% identity with the high-affinity phosphate transporter of Saccharomyces cerevisiae, PH084. The pho-5 null mutants have no obvious phenotype. Strains which contain a null mutation in pho-4, which encodes an additional high-affinity phosphate permease [Bowman et al., J. Bacteriol. 153 (1983) 292-296], also have no obvious phenotype. However, strains containing mutations in both pho-5 and pho-4 are unable to grow under phosphate-restrictive conditions.