FGSC #1625 Mating Types: a Species: Neurospora crassa
Genotype: en(am)-2;am;pe
Alleles: C24;32213;Y8743m
Linkage Group(s): IIR;VR;IR
Genetic Background: M
Mutagen: UV
Stock No. from Other Collection: 95-11
Depositor of Strain: MS
Strain of Opposite Mating Type: 0
Reference: Marie Shields Master's thesis U of U 1968
Reference: Shields M. Genetics 1968
Lesion: am amination deficient
Enzyme Name: NADP glutamate dehydrogenase
Lesion Information for Marker:
      Linkage Group of am: VR
      Markers Left of am: ure-2 (2%) and sp (4 to 8%)
      Markers Right ofam: gul-1(<<1%) and ace-5(<1%)
Marker description or requirements:
      VR. Right of ure-2 (2%) and sp (4 to 8%). Left of gul-1(<<1%) and ace-5(<1%) (122, 570, 579, 998). (R.W. Barratt, (cited in reference 1036) Structural gene for nicotinamide adenine dinucleotide phosphate (NADP)-glutamate dehydrogenase (336) (see Fig. 19), for which a complete 452-residue amino acid sequence has been obtained (465). Requires a source of alpha-amino nitrogen for growth, alanine being a good supplement (e.g., reference 997). Readily scorable at 25 C; leaky at 34°C (42). Leaky growth and adaptation on minimal medium are prevented by 0.02 M glycine (782, 783) or by en(am)-1, en(am)-2, or nit-2, q.v. The ammutants show abnormal regulation of reduced nicotinamide adenine dinucleotide (NADH)-glutamate dehydrogenase and are synergistic with nit-2 in this effect (226). Some am alleles (e.g., RU1) suppress the pyrimidine requirement caused by pyr-3 (CPS- ACT+) mutations (1137). Used for the first demonstration of complementation between alleles in vivo (344) (simultaneous with independent demonstration with ad-4). In vitro complementation (342). Used for studies of complementation mechanism (199, 200, 1120). Used for fine-structure mapping (337, 338). Control of intralocus recombination by rec-3(996-998). Used to study colinearity of the gene and gene product, internal suppressors (105, 340, 465), and the action of supersuppressors (954, 955). The functional defects in several mutant enzymes with single amino acid replacements have been defined: am1 mutant enzymes fail to bind NADPH (1120); am2, am3, am19, am130, and am131 enzymes are stabilized in the inactive conformational form (30, 200, 336, 556, 1044), and all are complementable by am1; am14 is osmotically reparable and is thought to have unstable quaternary structure (340). Used in a study showing glutamine to have a role as corepressor of uricase synthesis (1118). Used to study nitrogen assimilation and metabolism (503) and nitrogen metabolite repression (186, 291). Efficient procedure for selecting new am mutants (551). Spectrum of ultraviolet irradiation (UV)- and nitrous acid-induced mutants (554). Allele am17 has a chain-terminating codon of either the amber or ochre type at residue 313 of glutamate dehydrogenase, based on amino acid replacements in revertants and by ssu-1 (956). Allele 6 is a frameshift mutation with an insertion in the Ser5 codon (985). Allele 126 is highly unstable (553). Allele 132 is a deletion (1162). The am+ gene has been cloned in Escherichia coli(J.R.S. Fincham, personal communication) and transformed back into Neurospora (J.A. Kinsey, personal communication).
Reference for: am: 30. Ashby, B. , J. C. Wooton, and J. R. S. Finchmam. 1974. Slow conformational changes of a Neurospora glutamate dehydrogenase studied byprotein fluorescence. Biochem. J. 143:317-329.
Reference for: am: 42. Barratt, R. W. 1963. Effect of environmental conditions on the NADP-specific glutamic acid dehydrogenase in N. crassa. J. Gen. Microbiol. 33:33-42.
Reference for: am: 105. Brett, M. , G. K. Chambers, A. A. Holder, J. R. S. Fincham, and J. C. Wootton. 1976. Mutational amino acid replacements in N. crassa NADP-specific glutamate dehydrogenase. J. Mol. Biol. 106:1-22.
Reference for: am: 122. Burk, R. R. 1964. The location of i, enhancer of am. Neurospora Newsl. 6:27.
Reference for: am: 186. Chang, H. C. -P. and G. J. Sorger. 1976. Effect of ammonium ions on the induction of nitrite reductase in N. crassa. J. Bacteriol. 126:1002-1004.
Reference for: am: 199. Coddington, A. , and J. R. S. Fincham. 1965. Proof of hybrid enzyme formation in a case of inter-allelic complementation in N. crassa. J. Mol. Biol. 12:152-161.
Reference for: am: 200. Coddington, A. , J. R. S. Fincham, and T. K. Sundaram. 1966. Multiple active varieties of Neurospora glutamate dehydrogenase formed byhybridization between two inactive mutant proteins in vivo and in vitro. J. Mol. Biol. 17:503-512.
Reference for: am: 226. Dantzig, A. H. , F. L. Weigman, Jr. , and A. Nason. 1979. Regulation of glutamate dehydrogenases in nit-2 and am mutants of N. crassa. J. Bacteriol. 137:1333-1339.
Reference for: am: 291. Dunn-Coleman, N. S. , and R. H. Garrett. 1980. The role of glutamine synthetase and glutamine metabolism in nitrogen metaboliterepression, a regulatory phenomenon in the lower eukaryote Neurospora crassa. Mol. Gen. Genet. 179:25-32.
Reference for: am: 336. Fincham, J. R. S. 1962. Genetically determined multiple forms of glutamic dehydrogenase in Neurospora crassa. J. Mol. Biol. 4:257-274.
Reference for: am: 337. Fincham, J. R. S. 1967. Recombination within the am gene of Neurospora crassa. Genet. Res. 9:49-62.
Reference for: am: 338. Fincham, J. R. S. 1976. Recombination in the am gene of Neurospora crassa-- a new model for conversion polarity and an explanation for amarker effect. Heredity 36:81-89.
Reference for: am: 340. Fincham, J. R. S. , and A. J. Baron. 1977. The molecular basis of an osmotically reparable mutant of Neurospora crassa producing unstableglutamate dehydrogenase. J. Mol. Biol. 110:627-642.
Reference for: am: 342. Fincham, J. R. S. , and A. Coddington. 1963. Complementation at the am locus of Neurospora crassa:a reaction between different mutantforms of glutamic dehydrogenase. J. Mol. Biol. 6:361-373.
Reference for: am: 344. Fincham, J. R. S. , and J. A Pateman. 1957. Formation of an enzyme through complementary action of mutant "alleles" in separate nuclei in aheterocaryon. Nature 179:741-742.
Reference for: am: 465. Holder, A. A. , J. C. Wootton, A. J. Baron, G. K. Chambers, and J. R. S. Fincham. 1975. The amino acid sequence of NeurosporaNADP-specific glutamate degydrogenase. Peptic and chymotryptic peptides and the complete sequence. Biochem. J. 149:757-773.
Reference for: am: 503. Hummelt, G. , and J. Mora. 1980. NADH-dependent glutamate synthase and nitrogen metabolism in Neurospora crassa. Biochem. Biophys. Res. Commun. 92:127-133.
Reference for: am: 551. Kinsey, J. A. 1977. Direct selective procedure for isolating Neurospora mutants defective in nicotinamide adenine dinucleotide phosphatespecific glutamate dehydrogenase. J. Bacteriol. 132:751-756.
Reference for: am: 553. Kinsey, J. A. , and J. R. S. Fincham. 1979. An unstable allele of the am locus of Neurospora crassa. Genetics 93:577-586.
Reference for: am: 554. Kinsey, J. A. , and B. -S. T. Hung. 1981. Mutation at the am locus of Neurospora crassa. Genetics 99:405-414.
Reference for: am: 556. Kinsey, J. A. , J. R. S. Fincham, M. A. M. Siddig, and M. Keighren. 1980. New mutational variants of Neurospora NADP-specific glutamatedehydrogenase. Genetics 95:305-316.
Reference for: am: 570. Kolmark, H. G. 1969. Genetic studies of urease mutants in Neurospora crassa. Mutat. Res. 8:51-63.
Reference for: am: 579. Kuwana, H. , and R. P. Wagner. 1969. The iv-3 mutants of Neurospora crassa. I. Genetic and biochemical characteristics. Genetics 62:479-485.
Reference for: am: 782. Pateman, J. A. 1956. The stability of an adaptive system in Neurospora. Microb. Genet. Bull. 14:22-25.
Reference for: am: 783. Pateman, J. A. 1957. Back-mutation studies at the am locus in Neurospora crassa. J. Genet. 55:444-455.
Reference for: am: 954. Seale, T. W. 1972. Super-suppressors in Neurospora crassa. I. Induction, genetic localization and relationship to a missense suppressor. Genetics 70:385-396.
Reference for: am: 955. Seale, T. W. 1976. Super-suppressor action spectrum in Neurospora. Mol. Gen. Genet. 148:105-108.
Reference for: am: 956. Seale, T. W. , M. Brett, A. J. Baron, and J. R. S. Fincham. 1977. Amino acid replacements resulting from suppression and missense reversionof a chain-terminator mutation in Neurospora. Genetics 86:261-274.
Reference for: am: 985. Siddig, M. A. M. , J. A. Kinsey, J. R. S. Fincham, and M. Keighren. 1980. Frameshift mutations affecting the N-terminal sequence ofNeurospora NADP-specific glutamate dehydrogenase. J. Mol. Biol. 137:125-135.
Reference for: am: 996. Smyth, D. R. 1970. Genetic control of recombination in the amination-1 region of Neurospora crassa. Ph. D. thesis, Australian NationalUniversity,Canberra.
Reference for: am: 997. Smyth, D. R. 1971. Effect of rec-3 on polarity of recombination in the amination-1 locus of Neurospora crassa. Aust. J. Biol. Sci. 24:97-106.
Reference for: am: 998. Smyth, D. R. 1973. Action of rec-3 on recombination near the amination-1 locus of Neurospora crassa. Aust. J. Biol. Sci. 26:439-444.
Reference for: am: 1036. Strickland, W. N. , D. D. Perkins, and C. C. Veatch. 1959. Linkage data for group V markers in Neurospora. Genetics 44:1221-1226.
Reference for: am: 1044. Sundaram, T. K. , and J. R. S. Fincham. 1964. A mutant enzyme in Neurospora crassa interconvertible between electrophoretically distinctactive and inactive forms. J. Mol. Biol. 10:423-437.
Reference for: am: 1118. Wang, L. -W. C, and G. A. Marzluf. 1979. Nitrogen regulation of uricase synthesis in Neurospora crassa. Mol. Gen. Genet. 176:385-392.
Reference for: am: 1120. Watson, D. H. , and J. C. Wootton. 1977. Affinity chromatography of Neurospora NADP-specific glutamate dehydrogenase, its mutationalvariants and hybrid hexamers. Biochem. J. 167:95-108.
Reference for: am: 1137. Wieland, C. R. , and K. J. McDougall. 1969. Suppression of pyr-3 mutants by am mutants in Neurospora. Genetics 61:s62-s63 (Abstr. ).
Reference for: am: 1162. Wootton, J. C. , M. J. Fraser, and A. J. Baron. 1980. Efficient transformation of germinating Neurospora conidia using total nuclear DNAfragments. Neurospora Newsl. 27:33.
Lesion: pe peach
Lesion Information for Marker:
      Linkage Group of pe: IIR
      Markers Left of pe: nuc-2 (4%)
      Markers Right ofpe: arg-12 (1 to 5%)
Marker description or requirements:
      IIR. Between nuc-2 (4%) and arg-12 (1 to 5%) (593, 816). (613) Peach-colored conidia and short hyphae formed, more uniformly than by the wild type, as a lawn close to surface of agar. Distinctive morphology (46, 613). Added arginine increases macroconidiation and tends to obscure scoring of peat 25 C, but not at 39°C. pe single mutants produce both macro- and microconidia. pe fl double mutants produce abundant grey microconidia and no macroconidia (46, 700) (see fl). See col-1, col-4, and references 415 and 416 for interactions with other genes. Called m (microconidial) or pem in some contexts.
Reference for: pe: 46. Barratt, R. W. and L. Garnjobst. 1949. Genetics of a colonial microconidiating mutant strain of N. crassa. Genetics 34:351-369.
Reference for: pe: 593. Lehman, J. F. , M. K. Gleason, S. K. Ahlgren, and R. L. Metzenberg. 1973. Regulation of phosphate metabolism in Neurospora crassa. Characterization of regulatory mutants. Genetics 75:61-73.
Reference for: pe: 613. Lindegren, C. C. , and G. Lindegren. 1939. Non-random crossing-over in the second chromosome of Neurospora crassa. Genetics 24:1-7.
Reference for: pe: 700. Munkres, K. D. 1977. Selection of improved microconidial strains of Neurospora crassa. Neurospora Newsl. 24:9-10.
Reference for: pe: 816. Perkins, D. D. , D. Newmeyer, C. W. Taylor, and D. C. Bennett. 1969. New markers and map sequences in Neurospora crassa, with adescription of mapping by duplication coverage, and of multiple translocation stocks for testing linkage. Genetica 40:247-278.
Lesion: en(am)-2 enhancer-2 of am
Enzyme Name: glutamate synthase
Lesion Information for Marker:
      Linkage Group of en(am)-2: IIR
      Markers Left of en(am)-2: Linked near pe
Marker description or requirements:
      IIR. Linked near pe (983).In en(am)-2;am double mutants, en(am)-2 counteracts leakiness of am on minimal medium. en(am)-2;am strains grow well on L-alanine (25 mM) or 0.5% casein hydrolysate (983) or on glutamate (5 mM) (293). The single mutant en(am)-2without am grows normally on minimal medium. Mutant en(am)-2 lacks glutamate synthase (GOGAT) (see Fig. 19). The double mutant en(am)-2;am lacks NADP-glutamate dehydrogenase and GOGAT activities (293). Frequent revertants of the double mutant en(am)-2;am on suboptimal medium are attributed to back-mutation at am (983). Formerly called en-am.
Reference for: en(am)-2: 293. Dunn-Coleman, N. S. , E. A. Robey, A. B. Tomsett, and R. H. Garrett. 1981. Glutamate synthase levels in Neurospora crassa mutants alteredwith respect to nitrogen metabolism. Mol. Cell. Biol. 1:158-164.
Reference for: en(am)-2: 983. Shields, M. 1968. A mutation which prevents adaptation of am mutants of Neurospora crassa. M. S. thesis, University of Utah.


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