RNA recognition motif 3 (RRM3) found in plant polypyrimidine tract-binding protein homolog 1 and 2 (PTBPH1 and PTBPH2)
This subfamily corresponds to the RRM3 of PTBPH1 and PTBPH2. Although their biological roles remain unclear, PTBPH1 and PTBPH2 show significant sequence similarity to polypyrimidine tract binding protein (PTB) that is an important negative regulator of alternative splicing in mammalian cells and also functions at several other aspects of mRNA metabolism, including mRNA localization, stabilization, polyadenylation, and translation. Both, PTBPH1 and PTBPH2, contain three RNA recognition motifs (RRM), also known as RBD (RNA binding domain) or RNP (ribonucleoprotein domain).