1YRN

CRYSTAL STRUCTURE OF THE MATA1/MATALPHA2 HOMEODOMAIN HETERODIMER BOUND TO DNA

Summary for 1YRN

• Entry DOI: 10.2210/pdb1yrn/pdb
• Descriptor: DNA (5'-D(*TP*AP*CP*AP*TP*GP*TP*AP*AP*TP*TP*TP*AP*TP*TP*AP*C P*AP*TP*CP*A)-3'), DNA (5'-D(*TP*AP*TP*GP*AP*TP*GP*TP*AP*AP*TP*AP*AP*AP*TP*TP*A P*CP*AP*TP*G)-3'), PROTEIN (MAT A1 HOMEODOMAIN), ... (5 entities in total)
• Functional Keywords: complex, dna-binding protein, dna, dna binding protein-dna complex, dna binding protein/dna
• Biological source: Saccharomyces cerevisiae (baker's yeast); More
• Cellular location: Nucleus: Q6B2C0
• Total number of polymer chains: 4
• Total formula weight: 29817.23

Authors

Li, T.,Stark, M.R.,Johnson, A.D.,Wolberger, C. (deposition date: 1995-11-02, release date: 1996-01-29, Last modification date: 2024-02-14)

Primary citation

Li, T.,Stark, M.R.,Johnson, A.D.,Wolberger, C.
Crystal structure of the MATa1/MAT alpha 2 homeodomain heterodimer bound to DNA.
Science, 270:262-269, 1995

PubMed Abstract: The Saccharomyces cerevisiae MATa1 and MAT alpha 2 homeodomain proteins, which play a role in determining yeast cell type, form a heterodimer that binds DNA and represses transcription in a cell type-specific manner. Whereas the alpha 2 and a1 proteins on their own have only modest affinity for DNA, the a1/alpha 2 heterodimer binds DNA with high specificity and affinity. The three-dimensional crystal structure of the a1/alpha 2 homeodomain heterodimer bound to DNA was determined at a resolution of 2.5 A. The a1 and alpha 2 homeodomains bind in a head-to-tail orientation, with heterodimer contacts mediated by a 16-residue tail located carboxyl-terminal to the alpha 2 homeodomain. This tail becomes ordered in the presence of a1, part of it forming a short amphipathic helix that packs against the a1 homeodomain between helices 1 and 2. A pronounced 60 degree bend is induced in the DNA, which makes possible protein-protein and protein-DNA contacts that could not take place in a straight DNA fragment. Complex formation mediated by flexible protein-recognition peptides attached to stably folded DNA binding domains may prove to be a general feature of the architecture of other classes of eukaryotic transcriptional regulators.

PubMed: 7569974

Experimental method

X-RAY DIFFRACTION (2.5 Å)