Like many other transcription factors, the leucine-zipper-containing
transcription factors bind DNA as dimers. A leucine zipper is formed by
two a helices, one from each monomer. The
helices are held together by hydrophobic interactions between leucine residues,
which are located on one side of each helix. Examples include AP-1, CREB, and Gcn4.
(a)
(b)
Figure 4-F-5. (a) The domain organization
of the transcription factor Jun. (b) The structure of the AP-1/DNA
complex. AP-1 is a dimer formed by Jun and its homologous protein Fos.
It contains a leucine zipper motif where two a
helices look like a zipper with leucine residues (green color) lining on the
inside of the zipper. PDB ID = 1FOS.
Review article:
CCAAT/enhancer-binding
proteins: structure, function and regulation - Biochem. J., 2002.
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