Solution structure of the nonmethyl-CpG-binding CXXC domain of the leukaemia-associated MLL histone methyltransferase.
Methylation of CpG dinucleotides is the major epigenetic modification of mammalian genomes, critical for regulating chromatin structure and gene activity. The mixed-lineage leukaemia (MLL) CXXC domain selectively binds nonmethyl-CpG DNA, and is required for transformation by MLL fusion proteins that commonly arise from recurrent chromosomal translocations in infant and secondary treatment-related acute leukaemias. To elucidate the molecular basis of nonmethyl-CpG DNA recognition, we determined the structure of the human MLL CXXC domain by multidimensional NMR spectroscopy. The CXXC domain has a novel fold in which two zinc ions are each coordinated tetrahedrally by four conserved cysteine ligands provided by two CGXCXXC motifs and two distal cysteine residues. We have identified the CXXC domain DNA binding interface by means of chemical shift perturbation analysis, cross-saturation transfer and site-directed mutagenesis. In particular, we have shown that residues in an extended surface loop are in close contact with the DNA. These data provide a template for the design of specifically targeted therapeutics for poor prognosis MLL-associated leukaemias.
Allen
Mark D
MD
Centre for Protein Engineering, Cambridge, UK.
Grummitt
Charles G
CG
Hilcenko
Christine
C
Min
Sandra Young
SY
Tonkin
Louise M
LM
Johnson
Christopher M
CM
Freund
Stefan M
SM
Bycroft
Mark
M
Warren
Alan J
AJ
D000595:Amino Acid Sequence; D002151:Calorimetry; D018899:CpG Islands / Q000235:genetics*; D004247:DNA / Q000378:metabolism; D004252:DNA Mutational Analysis; D000076983:Histone Methyltransferases; D011495:Histone-Lysine N-Methyltransferase / Q000737:chemistry*; D006801:Humans; D007223:Infant; D007938:Leukemia / Q000378:metabolism*; D008958:Models, Molecular; D008969:Molecular Sequence Data; D016296:Mutagenesis; D051788:Myeloid-Lymphoid Leukemia Protein / Q000737:chemistry*; D009363:Neoplasm Proteins / Q000737:chemistry*; D011485:Protein Binding; D011496:Protein Methyltransferases; D017433:Protein Structure, Secondary; D017434:Protein Structure, Tertiary; D016415:Sequence Alignment; D012996:Solutions; D021241:Spectrometry, Mass, Electrospray Ionization
C497422:KMT2A protein, human; D009363:Neoplasm Proteins; D012996:Solutions; D051788:Myeloid-Lymphoid Leukemia Protein; D004247:DNA; D000076983:Histone Methyltransferases; D011496:Protein Methyltransferases; D011495:Histone-Lysine N-Methyltransferase