Homodimer. The measured mass is that of the PLP-bound protein. Belongs to the UPF0425 family. Despite a certain similarity to SelA, PubMed:16201757 reported that this protein does not harbor SelA activity, i.e. it fails to bind to Ser-tRNA(Sec) and is not able to convert this substrate to selenocysteinyl-tRNA(Sec). It also does not convert O-phosphoseryl-tRNA(Sec) to selenocysteinyl-tRNA(Sec).