Theoretical studies of the oxidized and reduced states of a model for the active site of rubredoxin

Although non-heme iron-sulfur proteins are ubiquitous among living systems, their role in biological processes is understood in only a few systems and even in these cases the details of the electron transfer and chemical processes they promote have not been elucidated. The physical propertes are best understood for rubredoxin (Rd, hereafter), plant ferredoxin (Fd, hereafter), bacterial ferredoxin, and high potential iron-sulfur protein containing one, two, four, and eight irons, respectively, with each iron tetrahedrally coordinated to four sulfurs, and contained in clusters of one, two, or four irons. In this initial study we use ab initio quality theoretical methods to examine the electronic properties of the active site of oxidized and reduced Rd for several geometries.