InterPro domain: IPR012900

This region is often found to the N terminus of the basic-leucine zipper domain ( IPR004827 ). It is between 150 and 200 amino acids in length. The N-terminal half of this domain is rich in proline residues and has been termed the PRD (proline rich domain) [ 1 ], whereas the C-terminal half is more polar and has been called the MFMR (multifunctional mosaic region). According to their motif composition, proteins containing this domain can be classified into three sub-families called A, B and C [ 2 ]. It has been suggested that some of these motifs may be involved in mediating protein-protein interactions [ 3 ]. The MFMR region contains a nuclear localisation signal in bZIP opaque and GBF-2 [ 3 ]. The MFMR also contains a transregulatory activity in TAF-1. The MFMR in CPRF-2 contains cytoplasmic retention signals [ 3 ].

1. Plant bZIP G-box binding factors. Modular structure and activation mechanisms. Eur. J. Biochem. 268, 5655-66
2. Novel conserved sequence motifs in plant G-box binding proteins and implications for interactive domains. Nucleic Acids Res. 22, 470-8