Sequence conservation in the Saccharomyces and Kluveromyces GAL11 transcription activators suggests functional domains.
Efficient transcription of many Saccharomyces cerevisiae genes requires the GAL11 Protein. GAL11 belongs to a class of transcription activator that lacks a DNA-binding domain. Such proteins are thought to activate specific genes by complexing with DNA-bound proteins. To begin to understand the domain structure-function relationships of GAL11 we cloned and sequenced a homologue from the yeast Kluyveromyces lactis, Kl-GAL11. The two predicted GAL11 proteins show high overall amino acid conservation and an unusual amino acid composition including 18% glutamine, 10% asparagine (S. cerevisiae) or 7% (K. lactis), and 8% proline (K. lactis) or 5% (S. cerevisiae) residues. Both proteins have runs of pure glutamines. Sc-GAL11 has glutamine-alanine runs but in Kl-GAL11 the alanines in such runs are replaced by proline and other residues. The primary sequence similarity is reflected in functional similarity since a gal11 mutation in K. lactis creates phenotypes similar to those seen previously in gal11-defective S. cerevisiae. In addition, Kl-GAL11 complements a gal11-defect in S. cerevisiae by partially restoring induction of GAL1 expression, growth on nonfermentable carbon sources, and phosphorylation of GAL4.
Department of Biological Chemistry, Milton S. Hershey Medical Center, Pennsylvania State University, Hershey 17033.
L M
LM
Mylin
C J
CJ
Gerardot
J E
JE
Hopper
R C
RC
Dickson
D000595:Amino Acid Sequence; D001483:Base Sequence; D015153:Blotting, Western; D003001:Cloning, Molecular; D005656:Fungal Proteins / Q000737:chemistry / Q000235:genetics* / Q000378:metabolism; D005690:Galactose / Q000494:pharmacology; D015966:Gene Expression Regulation, Fungal / Q000187:drug effects; D005816:Genetic Complementation Test; D007716:Kluyveromyces / Q000235:genetics*; D007785:Lactose / Q000494:pharmacology; D056892:Mediator Complex; D008969:Molecular Sequence Data; D009154:Mutation / Q000235:genetics; D010766:Phosphorylation; D012441:Saccharomyces cerevisiae / Q000235:genetics*; D029701:Saccharomyces cerevisiae Proteins; D012689:Sequence Homology, Nucleic Acid; D015534:Trans-Activators; D014157:Transcription Factors / Q000737:chemistry / Q000235:genetics* / Q000378:metabolism; D001616:beta-Galactosidase / Q000235:genetics / Q000378:metabolism
D005656:Fungal Proteins; C058337:GAL11 protein, S cerevisiae; D056892:Mediator Complex; D029701:Saccharomyces cerevisiae Proteins; D015534:Trans-Activators; D014157:Transcription Factors; D001616:beta-Galactosidase; D007785:Lactose; D005690:Galactose