title: Identification of the gene at the pmg locus, encoding system II, the general amino acid transporter in Neurospora crassa.
abstract: Mutations at the pmg locus in Neurospora crassa cause a deficiency in a transport system for a broad range of amino acids. We have isolated a gene that encodes a protein with a high degree of sequence similarity to the GAP1 general amino acid permease in Saccharomyces cerevisiae. Our data indicate that this is the gene at the pmg locus. It encodes a 572-residue protein with a molecular mass of 62,649 Da. The predicted secondary structure has 12 membrane-spanning regions, a feature characteristic of a superfamily of permease proteins. Inactivation of the gene yielded a mutant strain with the same phenotype as the pmg- strain, and a cosmid containing a functional copy of the gene rescued the pmg- strain. Although the pmg- strain has previously been assayed in a genetic background that contains mutations in genes for two other amino acid transport systems, we have found conditions in which the pmg- strain has an identifiable phenotype in an otherwise wild-type genetic background.
authors.affiliation: Department of Molecular, Cell, and Developmental Biology, University of California, Santa Cruz, CA 95064, USA.
authors.forename: E
authors.initials: E
authors.lastname: Margolis-Clark
authors.forename: I
authors.initials: I
authors.lastname: Hunt
authors.forename: S
authors.initials: S
authors.lastname: Espinosa
authors.forename: B J
authors.initials: BJ
authors.lastname: Bowman
mesh_terms: D000595:Amino Acid Sequence; D026905:Amino Acid Transport Systems / Q000235:genetics*; D001483:Base Sequence; D001692:Biological Transport; D004271:DNA, Fungal; D005656:Fungal Proteins / Q000235:genetics* / Q000378:metabolism; D020868:Gene Silencing; D026901:Membrane Transport Proteins / Q000235:genetics; D008969:Molecular Sequence Data; D009154:Mutation; D009492:Neurospora crassa / Q000201:enzymology / Q000235:genetics*; D010641:Phenotype; D020703:ras GTPase-Activating Proteins / Q000235:genetics
chemical_list: D026905:Amino Acid Transport Systems; D004271:DNA, Fungal; D005656:Fungal Proteins; D026901:Membrane Transport Proteins; D020703:ras GTPase-Activating Proteins