Summary
Fermentation of maltose by Saccharomyces strains depends on the presence of any one of five unlinked MAL loci (MAL1, MAL2, MAL3, MAL4 or MAL6). Earlier mutational analyses of MAL2 and MAL6 containing strains have identified a single complementation group at each of these two loci. However complementation analysis between naturally occurring Mal− Saccharomyces strains isolated from the wild demonstrated the presence of two complementation groups (designated MALp and MALg) at the MAL1, MAL3 and MAL6 loci. The available evidence suggests that the MALp gene is functionally equivalent to the complementation group identified by mutational analysis at the MAL6 locus and that this gene encodes a protein involved in the regulation of the coordinate induction of both maltase and maltose permease synthesis.
In this paper we report the isolation, in a well characterized MAL1 strain, of 47 mutants unable to ferment maltose. All the mutants, with one exception, map at the MAL1 locus. These mal1 mutants, except for one, are recessive to MAL1 and fall into two major complementation groups. Evidence is presented that these two classes of mutants identify both a gene involved in the regulation of maltose fermentation (MAL1R) and a gene involved in maltose transport (MAL1T). We also report here the isolation of a temperature sensitive maltose nonfermenting mutant mapping at the MAL1 locus identifying a third gene (MAL1S) at this locus. The maltase synthesized by this mutant, when assayed in cell-free extracts, is significantly more thermolabile than the wild type enzyme. Our findings demonstrate that MAL1 is a complex locus comprising at least three genes: MAL1R, a gene involved in the coordinate regulation of the synthesis of maltase and maltose transport; MAL1T, a gene encoding a component of the maltose transport system; and MAL1S, a likely candidate for the structural gene for maltase.
Similar content being viewed by others
References
Barnett JA (1976) The utilization of sugars by yeast. Adv Carbohydr Chem Biochem 32:125–134
Bolivar F (1978) Construction and characterization of new cloning vehicles. III. Derivatives of plasmid pBR322 carrying unique EcoRI sites for selection of EcoRI generated recombinant DNA molecules. Gene 4:121–136
Broach JF, Strathern JN, Hicks JB (1979) Transformation in yeast: Development of a hybrid cloning vector and isolation of the CAN1 gene. Gene 8:121–133
Carlson M, Osmond BC, Botstein D (1981) SUC genes of yeast: A dispersed gene family. Cold Spring Harbor Symp Quant Biol 45(B):799–803
Chow T, Goldenthal MJ, Cohen JD, Hegde M, Marmur J (1983) Identification and physical characterization of yeast maltase structural genes. Mol Gen Genet 191:366–371
de Kroon RA, Koningsberger VV (1970) An inducible transport system for α-glucosides in protoplasts of Saccharomyces carlsbergensis. Biochim Biophys Acta 204:590–609
De La Fuente G, Sols A (1962) Transport of sugars in yeast. II. Mechanisms of utilization of disaccharides and related glycosides. Biochim Biophys Acta 56:49–62
Federoff HJ, Cohen JD, Eccleshall TR, Needleman RB, Buchferer BA, Giacalone J, Marmur J (1982) Isolation of a maltase structural gene from Saccharomyces carlsbergensis. J Bacteriol 149:1064–1070
Federoff HJ, Eccleshall TR, Marmur J (1983) The regulation of maltase synthesis in Saccharomyces carlsbergensis. J Bacteriol 154:1301–1308
Goldenthal MJ, Cohen JD, Marmur J (1983) Isolation and characterization of a maltose transport mutant in Saccharomyces cerevisiae. Curr Genet 7:195–199
Lam KB, Marmur J (1977) Isolation and characterization of Saccharomyces cerevisiae glycolytic pathway mutants. J Bacteriol 130:746–749
Michels CA, Needleman RB (1983) A genetic and physical analysis of the MAL1 and MAL3 standard strains of Saccharomyces cerevisiae. Mol Gen Genet 191:225–230
Naumov GI (1970) Comparative genetics of yeast. IV. Identification of maltose complementing factors in Saccharomyces. Genetika 6:121–124
Naumov GI (1976) Comparative genetics of yeast. XVI. Maltose fermenting genes in Saccharomyces carlsbergensis strain NCYC74. Genetika 12:87–100
Needleman RB, Kaback DB, Dubin RA, Perkins EL, Rosenberg NG, Sutherland KA, Forest DB, Michels CA (1984) MAL6 of Saccharomyces: A complex locus containing three genes required for maltose fermentation. Proc Natl Acad Sci USA 81:2811–2815
Needleman RB, Michels CA (1983) A repeated family of genes controlling maltose fermentation in Saccharomyces carlsbergensis. Mol Cell Biol 3:796–802
Rigby PWJ, Dieckmann M, Rhodes C, Berg P (1977) Labeling deoxyribonucleic acid to high specific activity in vitro by nick translation with DNA polymerase I. J Mol Biol 113:237–251
Sherman F, Fink GR, Lawrence CW (1974) Laboratory manual for methods in yeast genetics. Cold Spring Harbor Laboratory, Cold Spring Harbor, NY
Southern EM (1975) Detection of specific sequences among DNA fragments separated by gel electrophoresis. J Mol Biol 98:503–517
Spector T (1978) Refinement of the Coomassie blue method of protein quantitation. Anal Biochem 86:142–146
ten Berge AMA, Zoutewelle G, van de Poll KW (1973) Regulation of maltose fermentation in Saccharomyces carlsbergensis. I. The function of the gene MAL6, as recognized by mal6 mutants. Mol Gen Genet 123:233–246
Thomas PS (1980) Hybridization of denatured RNA and small DNA fragments transferred to nitrocellulose. Proc Natl Acad Sci USA 77:5201–5205
Zimmermann FK, Eaton NR (1974) Genetics of induction and catabolite repression of maltase synthesis in Saccharomyces cerevisiae. Mol Gen Genet 134:261–272
Author information
Authors and Affiliations
Additional information
Communicated by F. Kaudewitz
Rights and permissions
About this article
Cite this article
Cohen, J.D., Goldenthal, M.J., Buchferer, B. et al. Mutational analysis of the MAL1 locus of Saccharomyces: identification and functional characterization of three genes. Mol Gen Genet 196, 208–216 (1984). https://doi.org/10.1007/BF00328052
Received:
Issue Date:
DOI: https://doi.org/10.1007/BF00328052