Presented is a model of the SCL:E47bHLH with important regions annotated.The stem cell leukaemia protein (pink) is a regulator of haematopoietic development and is ectopically expressed in T-cell acute lymphoblastic leukaemia.It sequesters E47(yellow) and recruits oncogenic transcription factors such as LMO2.E47 is a transcription factor involved in lymphopoiesis and normally binds the KIX domain of CBP; low levels are associated with leukemia. SCL:E47 is a parallel left handed bundle of two helix-loop-helix motifs.Each motif contains a H1 portion that forms mostly hydrophobic interactions with the other protein and a H2 portion, rich in basic residues that binds the E box region of DNA with the sequence 5’C1A2G3A4T5G63’ bound by SCL and complimentary strand 5’C1A2T3C4T5G63’ bound by E47 at the major groove. After binding DNA other factors are recruited to form a larger protein complex involved in hematopoietic gene regulation. El Omari et al, Cell Reports, 2013.Bloor et al, Oncogene, 2005
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