Vertebrate ferredoxins are 12-14-kDa iron-sulfur proteins, some of which transfer electrons to mitochondrial cytochrome P450s. The function of many of these cytochrome P450s is to catalyze stereospecific hydroxylation of endogenous steroids. As part of our interest in the kidney mitochondrial 1 alpha-hydroxylation of 25-hydroxyvitamin D3, we have constructed an expression plasmid coding for a f...

The benzene dioxygenase from Pseudomonas putida ML2 is a multicomponent complex comprising a flavoprotein reductase, a ferredoxin, and a terminal iron-sulfur protein (ISP). The catalytic activity of the isolated complex shows a nonlinear relationship with protein concentration in cell extracts, with the limiting factor for activity in vitro being ferredoxin(BED). The relative levels of the thre...

Ferredoxin reductase (Fd-reductase) supplies electrons to mitochondrial steroid hydroxylase cytochrome P450 enzymes via a [2Fe-2S] ferredoxin. Chemical labeling studies with bovine Fd-reductase have implicated Lys-243 as important in binding to bovine ferredoxin (Hamamoto, I., Kazutaka, K., Tanaka, S., and Ichikawa, Y. (1988) Biochim. Biophys. Acta 953, 207-213). We have used site-directed muta...

Ferredoxins are soluble iron-sulfur proteins that are involved in numerous electron-transfer reactions. Plant-type ferredoxins, which carry a single [2Fe-2S] cluster, serve as the electron acceptors of Photosystem I. The ferredoxin from the thermophilic cyanobacterium Mastigocladus laminosus has unique thermostable properties. The isolated protein is active at temperatures of higher than 338 K....

We previously showed that cytotoxic necrotizing factor 1 (CNF1) contributes to Escherichia coli K1 invasion of human brain microvascular endothelial cells (HBMEC) and interacts with the receptor on the surface of HBMEC. CNF1 is the cytoplasmic protein, and it remains incompletely understood how CNF1 is secreted across the inner and outer membranes in E. coli K1. In order to investigate the gene...

Two mutants sensitive to heat stress for growth and impaired in NADPH dehydrogenase (NDH-1)-dependent cyclic electron transport around photosystem I (NDH-CET) were isolated from the cyanobacterium Synechocystis sp. strain PCC 6803 transformed with a transposon-bearing library. Both mutants had a tag in the same sll0272 gene, encoding a protein highly homologous to NdhV identified in Arabidopsis...

Working in synchrony, photosynthetic charge separation, electron transfer, and redox reactions generate proton motive force necessary for the synthesis of ATP and funneling of electrons toward stromal reducing equivalent NADPH. The last step of electron transfer from ferredoxin to NADP is catalyzed by ferredoxin-NADP oxidoreductase (FNR). Two proteins, TROL (thylakoid rhodanese-like) and Tic62 ...