leucine zipper domain found in c-Myc-binding protein and similar proteins
MycBP, also called associate of Myc 1 (AMY-1), is a novel c-Myc binding protein that may control the transcriptional activity of Myc. It stimulates the activation of E box-dependent transcription by Myc. This model corresponds to the conserved region that shows high sequence similarity with the leucine zipper (ZIP) domain located at the C-terminus of TGF-beta-stimulated clone-22 domain (TSC22D) family transcription factors. The first helix of ZIP is not basic and does not contain the consensus sequence, NXX(A)(A)XX(C/S)R, found in most basic region/leucine zipper (bZIP) proteins. Thus, the DNA-binding capability of the ZIP domain is not obvious. Similar to bZIP, ZIP forms homo- and heterodimers, resulting in many dimers that may have different effects on transcription.