FIGURE 10.

In vitro Fe-S cluster assembly assays. A, UV-visible absorption spectra of ISCU during Fe-S cluster assembly catalyzed by NFS1-ISD11. Spectra were collected at 60-min intervals. Absorption (ABS) at 400 nm and 456 nm are characteristic of [4Fe-4S] and [2Fe-2S] clusters, respectively. B, time course of Fe-S cluster assembly followed at 456 nm. Black line, reaction containing ISCU and catalyzed by NFS1 alone. Red line, reaction containing ISCU and catalyzed by NFS1-ISD11. C, time course of Fe-S cluster assembly followed at 456 nm. Black line, reaction containing ISCU and a catalytic amount of E. coli IscS. Red line, reaction containing ISCU and a catalytic amount of NFS1-ISD11. D, time course of Fe-S cluster assembly followed at 456 nm. Red line, reaction containing ISCU and a catalytic amount of NFS1-ISD11. Black line, reaction containing ISCU(N90A) and a catalytic amount of NFS1-ISD11. E, time course of Fe-S cluster assembly followed at 456 nm in the presence of a catalytic amount of NFS1-ISD11. Red line, reaction containing ISCU. Black line, Reaction containing ISCU and 1 eq of Zn²⁺.