Fate hollow ataraxia eclipse transcript Patch#

The bHLH DNA-binding fold contains an N-terminal basic helix that interacts with the major groove of DNA, followed by a loop and a second α-helix 15. Members of the bHLH family control essential biological processes ranging from cell growth, proliferation and metabolism 9, neurogenesis 10 and myogenesis 11, to the response to hypoxia 12, and circadian rhythms 13, 14. The human bHLH transcription factor (TF) family consists of 108 members that form pairs of homo- and heterodimers 1, 8. The nucleosomal E-box position and the type of bHLH dimerization domain jointly determine the histone contact, the affinity and the degree of competition and cooperativity with other nucleosome-bound factors. At internal E-boxes, the MYC-MAX leucine zipper can also interact with histones H2B and H3, and its binding is indirectly enhanced by OCT4 elsewhere on the nucleosome. Binding of tandem E-boxes 5, 6, 7 at endogenous DNA sequences occurs through direct interactions between two CLOCK-BMAL1 protomers and histones and is important for circadian cycling.

Fate hollow ataraxia eclipse transcript Patch#

Atop the H2A–H2B acidic patch 4, the CLOCK-BMAL1 Per-Arnt-Sim (PAS) dimerization domains engage the histone octamer disc. Structural studies with engineered or native nucleosome sequences show that MYC-MAX or CLOCK-BMAL1 triggers the release of DNA from histones to gain access.

Both transcription factors bind to E-boxes preferentially near the nucleosomal entry–exit sites. Here we investigate how chromatinized E-boxes are engaged by two structurally diverse bHLH proteins: the proto-oncogene MYC-MAX and the circadian transcription factor CLOCK-BMAL1 (refs. The basic helix–loop–helix (bHLH) family of transcription factors recognizes DNA motifs known as E-boxes (CANNTG) and includes 108 members 1. Nature volume 619, pages 385–393 ( 2023) Cite this article

Cooperation between bHLH transcription factors and histones for DNA access