“…In E. coli, these PLP-donor enzymes act as -lyases, catalyzing the cleavage of the C-S bond from Cys or the C-Se bond from Sec to Ala and S 0 or Se 0 , respectively (3,11,13). However, an interaction between SPS and NifS-like enzymes has not been described, although a structural basis for the interaction of E. coli CsdB and A. aeolicus SPS was proposed because the molecular surfaces surrounding the active sites of CsdB and SPS exhibit complementarity by molecular docking (10). It is possible that thioredoxin reductase, which is involved in selenite reduction, is also involved in delivering selenide for SPS (3,13).…”