TY - JOUR
T1 - Structural Basis for DNA Binding Specificity by the Auxin-Dependent ARF Transcription Factors
AU - Boer, D.R.
AU - Freire Rios, A.
AU - van den Berg, W.A.M.
AU - Saaki, T.
AU - Manfield, I.W.
AU - Kepinski, S.
AU - López-Vidrieo, I.
AU - Franco-Zorilla, J.M.
AU - de Vries, S.C.
AU - Solano, R.
AU - Weijers, D.
AU - Coll, M.
PY - 2014
Y1 - 2014
N2 - Auxin regulates numerous plant developmental processes by controlling gene expression via a family of functionally distinct DNA-binding auxin response factors (ARFs), yet the mechanistic basis for generating specificity in auxin response is unknown. Here, we address this question by solving high-resolution crystal structures of the pivotal Arabidopsis developmental regulator ARF5/MONOPTEROS (MP), its divergent paralog ARF1, and a complex of ARF1 and a generic auxin response DNA element (AuxRE). We show that ARF DNA-binding domains also homodimerize to generate cooperative DNA binding, which is critical for in vivo ARF5/MP function. Strikingly, DNA-contacting residues are conserved between ARFs, and we discover that monomers have the same intrinsic specificity. ARF1 and ARF5 homodimers, however, differ in spacing tolerated between binding sites. Our data identify the DNA-binding domain as an ARF dimerization domain, suggest that ARF dimers bind complex sites as molecular calipers with ARF-specific spacing preference, and provide an atomic-scale mechanistic model for specificity in auxin response.
AB - Auxin regulates numerous plant developmental processes by controlling gene expression via a family of functionally distinct DNA-binding auxin response factors (ARFs), yet the mechanistic basis for generating specificity in auxin response is unknown. Here, we address this question by solving high-resolution crystal structures of the pivotal Arabidopsis developmental regulator ARF5/MONOPTEROS (MP), its divergent paralog ARF1, and a complex of ARF1 and a generic auxin response DNA element (AuxRE). We show that ARF DNA-binding domains also homodimerize to generate cooperative DNA binding, which is critical for in vivo ARF5/MP function. Strikingly, DNA-contacting residues are conserved between ARFs, and we discover that monomers have the same intrinsic specificity. ARF1 and ARF5 homodimers, however, differ in spacing tolerated between binding sites. Our data identify the DNA-binding domain as an ARF dimerization domain, suggest that ARF dimers bind complex sites as molecular calipers with ARF-specific spacing preference, and provide an atomic-scale mechanistic model for specificity in auxin response.
KW - arabidopsis gene monopteros
KW - response elements
KW - vascular development
KW - plant development
KW - domains
KW - family
KW - embryo
KW - embryogenesis
KW - dimerization
KW - recognition
U2 - 10.1016/j.cell.2013.12.027
DO - 10.1016/j.cell.2013.12.027
M3 - Article
SN - 0092-8674
VL - 156
SP - 577
EP - 589
JO - Cell
JF - Cell
ER -