Structural highlights
Function
[MTAL2_YEAST] Mating type proteins are sequence specific DNA-binding proteins that act as master switches in yeast differentiation by controlling gene expression in a cell type-specific fashion. Transcriptional corepressor that binds cooperatively with MCM1 to a 31-basepair DNA sequence termed the a-specific gene (asg) operator, to repress the transcription of a-cell-specific genes. Additionally, in a/alpha diploid cells, binds cooperatively with the A1 protein to a 21-basepair DNA sequence termed the haploid-specific gene (hsg) operator, to repress transcription of haploid-specific genes and of MATALPHA1.[1]
Evolutionary Conservation
Check, as determined by ConSurfDB. You may read the explanation of the method and the full data available from ConSurf.
Publication Abstract from PubMed
The MAT alpha 2 homeodomain regulates the expression of cell type-specific genes in yeast. We have determined the 2.7 A resolution crystal structure of the alpha 2 homeodomain bound to a biologically relevant DNA sequence. The DNA in this complex is contacted primarily by the third of three alpha-helices, with additional contacts coming from an N-terminal arm. Comparison of the yeast alpha 2 and the Drosophila engrailed homeodomain-DNA complexes shows that the protein fold is highly conserved, despite a 3-residue insertion in alpha 2 and only 27% sequence identity between the two homeodomains. Moreover, the orientation of the recognition helix on the DNA is also conserved. This docking arrangement is maintained by side chain contacts with the DNA--primarily the sugar-phosphate backbone--that are identical in alpha 2 and engrailed. Since these residues are conserved among all homeodomains, we propose that the contacts with the DNA are also conserved and suggest a general model for homeodomain-DNA interactions.
Crystal structure of a MAT alpha 2 homeodomain-operator complex suggests a general model for homeodomain-DNA interactions.,Wolberger C, Vershon AK, Liu B, Johnson AD, Pabo CO Cell. 1991 Nov 1;67(3):517-28. PMID:1682054[2]
From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine.
References
- ↑ Johnson AD. Molecular mechanisms of cell-type determination in budding yeast. Curr Opin Genet Dev. 1995 Oct;5(5):552-8. PMID:8664541
- ↑ Wolberger C, Vershon AK, Liu B, Johnson AD, Pabo CO. Crystal structure of a MAT alpha 2 homeodomain-operator complex suggests a general model for homeodomain-DNA interactions. Cell. 1991 Nov 1;67(3):517-28. PMID:1682054
