Summary information and primary citation
- PDB-id
-
1hwt;
DSSR-derived features in text and
JSON formats; DNAproDB
- Class
- gene regulation-DNA
- Method
- X-ray (2.5 Å)
- Summary
- Structure of a hap1-DNA complex reveals dramatically
asymmetric DNA binding by a homodimeric protein
- Reference
-
King DA, Zhang L, Guarente L, Marmorstein R (1999):
"Structure
of a HAP1-DNA complex reveals dramatically asymmetric DNA
binding by a homodimeric protein."
Nat.Struct.Biol., 6, 64-71.
doi: 10.1038/4940.
- 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.
