multiple sulfur acceptors dock at iscs多个硫受体isc码头.pdfVIP

Synopsis Multiple Sulfur Acceptors Dock at IscS Kira Heller* Freelance Science Writer, Oakland, California, United States of America Like a busy dock, the enzyme IscS offers Cys328 that was substantially larger than a temporary berth to multiple protein the binding sites of IscU and TusA. vessels where they can load up with their To further explore the conserved area cargo of sulfur atoms. The sulfur is then around Cys328 and determine if other incorporated into essential biological IscS protein partners also docked there, structures such as the iron–sulfur clusters the researchers created a series of IscS that catalyze oxidation–reduction reac- mutant proteins in which single amino tions in the electron transport chain. acids distributed across the entire interact- Although the structure of IscS has been ing surface were changed in ways that they known for some time, it was not clear how predicted would affect the binding prop- it recognizes and discriminates among the erties. They then measured how these different incoming proteins. Do they dock mutations affected binding to IscU and at the same site on IscS, or do they have TusA, and to other known IscS partners: individual berths? Can they all moor at ThiI, which modifies tRNA by adding once, or do they have to wait their turn? In sulfur to specific nucleotides and partici- a new study in PLoS Biology, Rong Shi, pates in synthesis of the vitamin thiamine; Miroslaw Cygler, and colleagues investi- frataxin (CyaY in bacteria), which is gated these questions in a series of probably