Selenocysteine (Sec) is co-translationally incorporated into selenoproteins at a 
reprogrammed UGA codon. In mammals, this requires a dedicated machinery 
comprising a stem-loop structure in the 3' UTR RNA (the SECIS element) and the 
specific SECIS Binding Protein 2. In this report, disorder-prediction methods 
and several biophysical techniques showed that ca. 70% of the SBP2 sequence is 
disordered, whereas the RNA binding domain appears to be folded and functional. 
These results are consistent with a recent report on the role of the Hsp90 
chaperone for the folding of SBP2 and other functionally unrelated proteins 
bearing an RNA binding domain homologous to SBP2.