Purity > 85% as determined by SDS-PAGE. MW: 21.5kDa. Full Length: 1-156aa. N-terminal 10xHis-tagged and C-terminal Myc-tagged. Mus musculus (Mouse). Since they lack a putative transactivation domain, the small Mafs behave as transcriptional repressors when they dimerize among themselves. However, they seem to serve as transcriptional activators by dimerizing with other (usually larger) basic-zipper proteins and recruiting them to specific DNA-binding sites. Small Maf proteins heterodimerize with Fos and may act as competitive repressors of the NF-E2 transcription factor.