Characterization of flavin-containing monooxygenase 5 (FMO5) cloned from human and guinea pig: evidence that the unique catalytic properties of FMO5 are not confined to the rabbit ortholog.

Several full-length clones encoding the human and guinea pig orthologs of flavin-containing monooxygenase 5 (FMO5) have been isolated from libraries constructed with hepatic mRNA. The clones were detected by hybridization with the cDNA encoding FMO5 expressed in rabbit. The human and guinea pig cDNAs encode for proteins of 533 amino acids that contain putative pyrophosphate binding domains characteristic of mammalian FMOs.

Cloning, sequencing, distribution, and expression in Escherichia coli of flavin-containing monooxygenase 1C1. Evidence for a third gene subfamily in rabbits.

Two full-length cDNA clones (2.2 kilobases) encoding a newly recognized form of mammalian flavin-containing monooxygenase (FMO) have been isolated from independent libraries constructed with mRNA from different rabbits. The cDNAs encode a polypeptide of 533 amino acids which contains two putative pyrophosphate binding domains and a hydrophobic carboxyl terminus characteristic of FMOs.

Potential ligands to the [2Fe-2S] Rieske cluster of the cytochrome bc1 complex of Rhodobacter capsulatus probed by site-directed mutagenesis.

The Rieske protein of the ubiquinol-cytochrome c oxidoreductase (bc1 complex or b6f complex) contains a [2Fe-2S] cluster which is thought to be bound to the protein via two nitrogen and two sulfur ligands [Britt, R. D., Sauer, K.

Size of the amino acid side chain at position 158 of cytochrome b is critical for an active cytochrome bc1 complex and for photosynthetic growth of Rhodobacter capsulatus.

The nonphotosynthetic mutant R126 of Rhodobacter capsulatus has a cytochrome (cyt) bc1 complex (EC 1.10.2.

Chloroplast thylakoid proteins associated with sequestered proton-buffering domains. Plastocyanin contributes buffering groups to localized proton domains.

Thylakoid membrane proteins are organized so as to shield 30-50 nmol H+ (mg Chl)-1 from freely equilibrating with either the external or the lumen aqueous phases. Amine groups provide binding sites for this metastable buffering array and can be quantitatively measured by acetylation using [3H]acetic anhydride. The principle of the assay is that a metastable acidic domain will have relatively less of the reactive neutral form of the amine compared to the amount present after addition of an uncoupler.

Plastocyanin stimulation of whole chain and photosystem I electron transport in inside-out thylakoid vesicles.

Inside-out and right-side-out thylakoid vesicles were isolated from spinach chloroplasts by aqueous-polymer two-phase (dextran/polyethylene glycol) partitioning. Externally added plastocyanin stimulated the whole-chain and PSI electron transport rates in the inside-out thylakoid vesicles by about 500 and 350%, respectively, compared to about 50% stimulation for both assays in the fraction enriched in right-side-out vesicles. No apparent stimulation by plastocyanin was observed in unbroken Class II thylakoids.