ISSN:
1572-9540
Source:
Springer Online Journal Archives 1860-2000
Topics:
Physics
Notes:
Abstract Mössbauer, EPR, and biochemical techniques were used to characterize two dissimilatory sulfite reductases: desulforubidin fromDesulfovibrio baculatus strain DSM 1743 and desulfoviridin fromDesulfovibrio gigas. For each molecule of desulforubidin, there are two sirohemes and four [4Fe−4S] clusters. The [4Fe−4S] clusters are in the diamagnetic 2+ oxidation state. The sirohemes are high-spin ferric (S=5/2) and each siroheme is exchanged-coupled to a [4Fe−4S]2+ cluster. Such an exchange-coupled siroheme-[4Fe−4S] unit has also been found in the assimilatory sulfite reductase fromEscherichia coli/1/ and in a low-molecular weight sulfite reductase fromDesulfovibrio vulgaris/2/. For each molecule of defulfoviridin, there are two tetrahydroporphyrin groups and four [4Fe−4S]2+ clusters. To our surprise, we discovered that about 80% of the tetrahydroporphyrin groups, however, do not bind iron.
Type of Medium:
Electronic Resource
URL:
http://dx.doi.org/10.1007/BF02395536
