Determinants of T box protein specificity.
Members of the T box family of transcription factors play important roles in early development. Different members of the family exert different effects and here we show that much of the specificity of the Xenopus T box proteins Xbra, VegT and Eomesodermin resides in the DNA-binding domain, or T box. Binding site selection experiments show that the three proteins bind the same core sequence, but they select paired sites that differ in their orientation and spacing. Lysine 149 of Xbra is conserved in all Brachyury homologues, while the corresponding amino acid in VegT and Eomesodermin is asparagine. Mutation of this amino acid to lysine changes the inductive abilities of VegT and Eomesodermin to resemble that of Xbra.
Conlon
F L
FL
Division of Developmental Biology, National Institute for Medical Research, The Ridgeway, Mill Hill, London NW7 1AA, UK.
Fairclough
L
L
Price
B M
BM
Casey
E S
ES
Smith
J C
JC
D000595:Amino Acid Sequence; D000818:Animals; D001216:Asparagine / Q000235:genetics; D001665:Binding Sites; D004625:Embryo, Nonmammalian; D005260:Female; D005326:Fetal Proteins; D018507:Gene Expression Regulation, Developmental; D008239:Lysine / Q000235:genetics; D008969:Molecular Sequence Data; D017354:Point Mutation; D012091:Repetitive Sequences, Nucleic Acid; D017386:Sequence Homology, Amino Acid; D013379:Substrate Specificity; D020825:T-Box Domain Proteins / Q000235:genetics* / Q000378:metabolism*; D014981:Xenopus / Q000196:embryology / Q000235:genetics; D029867:Xenopus Proteins; D000098908:Brachyury Protein
D001216:Asparagine; D005326:Fetal Proteins; D008239:Lysine; D020825:T-Box Domain Proteins; D029867:Xenopus Proteins; D000098908:Brachyury Protein; C103223:EOMES protein, Xenopus; C116765:TBXT protein, Xenopus; C103966:VegT protein, Xenopus