Evidence for N-coordination to Fe in the [2Fe 2S] clusters of Thermus Rieske protein and phthalate dioxygenase from pseudomonas.

In 1964 J.S. Rieske and his co-workers isolated an iron and sulfide containing protein from beef heart mitochondria which, for lack of a specific function, has become generally known as the Rieske Fe/S protein. Subsequent studies showed that the protein is widely distributed in Nature. Recently, a Rieske- type protein was isolated from the plasma membrane of Thermus thermophilus. We have used electron nuclear double resonance (ENDOR) and electron spin echoe (ESE) techniques to demonstrate that the [2Fe 2S] clusters associated with this protein are bound in part by nitrogenous ligands.