1HWT

STRUCTURE OF A HAP1/DNA COMPLEX REVEALS DRAMATICALLY ASYMMETRIC DNA BINDING BY A HOMODIMERIC PROTEIN

Summary for 1HWT

• Entry DOI: 10.2210/pdb1hwt/pdb
• Descriptor: DNA (5'-D(*GP*CP*GP*CP*TP*AP*TP*TP*AP*TP*CP*GP*CP*TP*AP*TP*TP*AP*GP*C)-3'), DNA (5'-D(*GP*CP*TP*AP*AP*TP*AP*GP*CP*GP*AP*TP*AP*AP*TP*AP*GP*CP*GP*C)-3'), PROTEIN (HEME ACTIVATOR PROTEIN), ... (5 entities in total)
• Functional Keywords: transcription factor, asymmetry, gal4, complex activator-dna, gene regulation-dna complex, gene regulation/dna
• Biological source: Saccharomyces cerevisiae (baker's yeast); More
• Total number of polymer chains: 8
• Total formula weight: 63628.22

Authors

King, D.A.,Zhang, L.,Guarente, L.,Marmorstein, R. (deposition date: 1998-09-17, release date: 1999-11-10, Last modification date: 2024-04-03)

Primary citation

King, D.A.,Zhang, L.,Guarente, L.,Marmorstein, R.
Structure of a HAP1-DNA complex reveals dramatically asymmetric DNA binding by a homodimeric protein.
Nat.Struct.Biol., 6:64-71, 1999

PubMed Abstract: HAP1 is a member of a family of fungal transcription factors that contain a Zn2Cys6 binuclear cluster domain and bind as homodimers to sequences containing two DNA half sites. We have determined the 2.5 A crystal structure of HAP1 bound to a cognate upstream activation sequence from the CYC7 gene. The structure reveals that HAP1 is bound in a dramatically asymmetric manner to the DNA target. This asymmetry aligns the Zn2Cys6 domains in a tandem head-to-tail fashion to contact two DNA half sites, positions an N-terminal arm of one of the protein subunits to interact with the inter-half site base pairs in the DNA minor groove, and suggests a mechanism by which DNA-binding facilitates asymmetric dimerization by HAP1. Comparisons with the DNA complexes of the related GAL4, PPR1 and PUT3 proteins illustrate how a conserved protein domain can be reoriented to recognize DNA half sites of different polarities and how homodimeric proteins adopt dramatically asymmetric structures to recognize cognate DNA targets.

PubMed: 9886294
DOI: 10.1038/4940

Experimental method

X-RAY DIFFRACTION (2.5 Å)