Progress in succinate:quinone oxidoreductase research

This chapter discusses the progress in succinate:quinone oxidoreductase research. It reviews the progress made mainly within the last decade in understanding of the genetics, biogenesis, structure and functions of succinate:quinone oxidoreductases. The work on this class of enzymes has involved a vast amount of experimental efforts in many laboratories. As in many other fields of biological research, rapid advances have resulted from the increased use of a molecular biologist's approach, that is, a combination of molecular genetics, biochemistry and biophysical techniques. Succinate:quinone oxidoreductases are membrane bound enzymes that can catalyze the oxidation of succinate to fumarate coupled to the reduction of a quinone and the reduction of fumarate to succinate coupled to the oxidation of quinol. Succinate:quinone reductase (SQR), is present in strictly aerobic cells, and in vivo predominantly catalyzes the oxidation of succinate. Continued investigations of the structure of SQR and QFR enzymes will provide detailed, three-dimensional structural information, which is required for the better understanding of mechanisms of catalysis at the dicarboxylate and the quinone active sites and in the intra-molecular electron transfer.