This family is the second part of the minimal transactivation domain of erythroid-specific transcription factor EKFL in craniates. EKLF plays an important role in red blood cell development; it is post-translationally modified by ubiquitin on several lysine residues, and its turnover in the cell is regulated by ubiquitin-mediated degradation. In the first 90 residues at the N-terminus EKLF carries a minimal transactivation or TAD domain that is highly acidic. This minimal TAD of EKLF can be further subdivided into two independent domains EKLF_TAD1 (residues 1-40), pfam16832, and EKLF_TAD2 (residues 51-90) that are both capable of independently activating transcription. Both TAD1 and TAD2 are highly acidic and carry a PEST (sequence rich in proline, glutamic acid, serine, and threonine) region. Deletion of either PEST domain significantly slows down degradation of EKLF by ubiquitin. The minimal TAD has an overlapping activation/degradation function that is critical for the role of EKLF in red blood cell development.