third type I K homology (KH) RNA-binding domain found in poly(rC)-binding protein 4 (PCBP4) and similar proteins
PCBP4, also called alpha-CP4, or heterogeneous nuclear ribonucleoprotein E4, or hnRNP E4, is a single-stranded nucleic acid binding protein that binds preferentially to oligo dC. It regulates both basal and stress-induced p21 expression through binding p21 3'-UTR and modulating p21 mRNA stability. It also plays a role in the cell cycle and is implicated in lung tumor suppression. PCBP4 contains three K-homology (KH) RNA-binding domains. The model corresponds to the third one.