Enterococcus faecalis SufU scaffold protein enhances SufS desulfurase activity by acquiring sulfur from its cysteine-153

► Iron-sulfur cluster biogenesis in gram-positive bacteria. ► SufU is the E. faecalis scaffold protein and reconstitutes [4Fe-4S] cluster. ► SufS is the cysteine desulfurase enzyme enclosing a catalytically cys-365. ► SufU activates E. faecalis SufS desulfurase activity. ► Transpersulfurization reaction involves cys-365 of SufS and cys-153 of SufU.