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.
Mylin
L M
LM
Department of Biological Chemistry, Milton S. Hershey Medical Center, Pennsylvania State University, Hershey 17033.
Gerardot
C J
CJ
Hopper
J E
JE
Dickson
R C
RC
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