DNA-binding mechanism of the monomeric orphan nuclear receptor NGFI-B
Gretchen Meinke
& Paul B. Sigler
Department of Molecular Biophysics and Biochemistry
and the Howard Hughes Medical Institute, Yale University, 260
Whitney Avenue, New Haven, Connecticut
06511, USA.
The 2.7 Å X-ray crystal structure of the DNA-binding domain (DBD)
of the orphan nuclear receptor, nerve growth factor-induced-B (NGFI-B), complexed
to its high-affinity DNA target, represents the first structure analysis of
a nuclear receptor DBD bound as a monomer to DNA. The structure of the core
DBD and its interactions with the major groove of the DNA are similar to previously
crystallographically solved DBD−DNA complexes in this superfamily; however,
residues C-terminal to this core form a separate and unique substructure that
interacts extensively and in a sequence-specific way with the minor groove
of its DNA target, in particular with the characteristic 3 A-T base-pair identity
element that extends 5' to the usual nuclear receptor half-site (AGGTCA).
