Bacterial NADH-quinone oxidoreductases.
The NADH-quinone oxidoreductases of the bacterial respiratory chain could be divided in two groups depending on whether they bear an energy-coupling site. Those enzymes that bear the coupling site are designated as NADH dehydrogenase 1 (NDH-1) and those that do not as NADH dehydrogenase 2 (NDH-2). All members of the NDH-1 group analyzed to date are multiple polypeptide enzymes and contain noncovalently bound FMN and iron-sulfur clusters as prosthetic groups. The NADH-ubiquinone-1 reductase activities of NDH-1 are inhibited by rotenone, capsaicin, and dicyclohexylcarbodiimide. The NDH-2 enzymes are generally single polypeptides and contain noncovalently bound FAD and no iron-sulfur clusters. The enzymatic activities of the NDH-2 are not affected by the above inhibitors for NDH-1. Recently, it has been found that both of these types of the NADH-quinone oxidoreductase are present in a single strain of bacteria. The significance of the occurrence of these two types of enzymes in a single organism has been discussed in this review.
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Department of Molecular and Experimental Medicine, Research Institute of Scripps Clinic, La Jolla, California 92037.
D000595:Amino Acid Sequence; D001419:Bacteria / Q000201:enzymology*; D008969:Molecular Sequence Data; D010230:Paracoccus / Q000201:enzymology; D011808:Quinone Reductases / Q000378:metabolism*; D012689:Sequence Homology, Nucleic Acid
C041831:NADH dehydrogenase (quinone); D011808:Quinone Reductases