The leucine zipper motif. (A) Shown is a helical wheel analysis of a carboxyl terminal portion of the DNA binding protein C/EBP (Table 36–3). The amino
acid sequence is displayed end-to-end down the axis of a schematic α-helix. The helical wheel consists of seven spokes that correspond to the seven
amino acids that comprise every two turns of the α-helix. Note that leucine residues (L) occur at every seventh position (in this schematic C/EBP amino
acid residues 1, 8, 15, 22; see arrow). Other proteins with “leucine zippers” have a similar helical wheel pattern. (B) A schematic model of the DNA-binding
domain of C/EBP. Two identical C/EBP polypeptide chains are held in dimer formation by the leucine zipper domain of each polypeptide (denoted by the
white rectangles and attached orange shaded ovals). This association is required to hold the DNA binding domains of each polypeptide (the green shaded
Source: Regulation of Gene Expression, Harper's Illustrated Biochemistry, 30e
rectangles) in the proper conformation and register for DNA binding. (Courtesy of S McKnight.)
Citation: Rodwell VW, Bender DA, Botham KM, Kennelly PJ, Weil P. Harper's Illustrated Biochemistry, 30e; 2015 Available at:
http://mhmedical.com/ Accessed: July 31, 2017
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