RNA recognition motif (RRM) found in yeast RNA annealing protein YRA1 (Yra1p), yeast mRNA export protein mlo3 and similar proteins
This subfamily corresponds to the RRM of Yra1p and mlo3. Yra1p is an essential nuclear RNA-binding protein encoded by Saccharomyces cerevisiae YRA1 gene. It belongs to the evolutionarily conserved REF (RNA and export factor binding proteins) family of hnRNP-like proteins. Yra1p possesses potent RNA annealing activity and interacts with a number of proteins involved in nuclear transport and RNA processing. It binds to the mRNA export factor Mex67p/TAP and couples transcription to export in yeast. Yra1p is associated with Pse1p and Kap123p, two members of the beta-importin family, further mediating transport of Yra1p into the nucleus. In addition, the co-transcriptional loading of Yra1p is required for autoregulation. Yra1p consists of two highly conserved N- and C-terminal boxes and a central RNA recognition motif (RRM), also termed RBD (RNA binding domain) or RNP (ribonucleoprotein domain). This subfamily includes RNA-annealing protein mlo3, also termed mRNA export protein mlo3, which has been identified in fission yeast as a protein that causes defects in chromosome segregation when overexpressed. It shows high sequence similarity with Yra1p.