Energetic and functional contribution of residues in the core binding factor beta (CBFbeta ) subunit to heterodimerization with CBFalpha.
Core-binding factors (CBFs) are a small family of heterodimeric transcription factors that play critical roles in several developmental pathways, including hematopoiesis and bone development. Mutations in CBF genes are found in leukemias and bone disorders. CBFs consist of a DNA-binding CBFalpha subunit (Runx1, Runx2, or Runx3) and a non-DNA-binding CBFbeta subunit. CBFalpha binds DNA in a sequence-specific manner, whereas CBFbeta enhances DNA binding by CBFalpha. Recent structural analyses of the DNA-binding Runt domain of CBFalpha and the CBFbeta subunit identified the heterodimerization surfaces on each subunit. Here we identify amino acids in CBFbeta that mediate binding to CBFalpha. We determine the energy contributed by each of these amino acids to heterodimerization and the importance of these residues for in vivo function. These data refine the structural analyses and further support the hypothesis that CBFbeta enhances DNA binding by inducing a conformational change in the Runt domain.
Tang
Y Y
YY
Department of Biochemistry, Dartmouth Medical School, Hanover, New Hampshire 03755, USA. Yen-Yee.Tang@dartmouth.edu
Shi
J
J
Zhang
L
L
Davis
A
A
Bravo
J
J
Warren
A J
AJ
Speck
N A
NA
Bushweller
J H
JH
D000596:Amino Acids / Q000737:chemistry; D000818:Animals; D015153:Blotting, Western; D002454:Cell Differentiation; D050659:Core Binding Factor Alpha 1 Subunit; D050657:Core Binding Factor alpha Subunits; D018360:Crystallography, X-Ray; D004268:DNA-Binding Proteins / Q000737:chemistry* / Q000235:genetics / Q000378:metabolism*; D019281:Dimerization; D004305:Dose-Response Relationship, Drug; D004622:Embryo, Mammalian / Q000378:metabolism; D005838:Genotype; D007700:Kinetics; D009682:Magnetic Resonance Spectroscopy; D051379:Mice; D008954:Models, Biological; D008958:Models, Molecular; D016297:Mutagenesis, Site-Directed; D009154:Mutation; D011487:Protein Conformation; D017433:Protein Structure, Secondary; D017434:Protein Structure, Tertiary; D011993:Recombinant Fusion Proteins / Q000378:metabolism; D012190:Retroviridae / Q000235:genetics; D013234:Stem Cells / Q000378:metabolism; D050656:Transcription Factor AP-2; D014157:Transcription Factors / Q000737:chemistry* / Q000235:genetics / Q000378:metabolism*; D020798:Two-Hybrid System Techniques; D001616:beta-Galactosidase / Q000378:metabolism
D000596:Amino Acids; D050659:Core Binding Factor Alpha 1 Subunit; D050657:Core Binding Factor alpha Subunits; D004268:DNA-Binding Proteins; D011993:Recombinant Fusion Proteins; C493716:Runx2 protein, mouse; D050656:Transcription Factor AP-2; D014157:Transcription Factors; C406688:core binding factor alpha; D001616:beta-Galactosidase