Heterologous expression of Halomonas halodenitrificans nitric oxide reductase and its N-terminally truncated NorC subunit in Escherichia coli.

Halomonas halodenitrificans nitric oxide reductase (NOR) is the membrane-bound heterodimer complex of NorC, which contains a low-spin heme c center, and NorB, which contains a low-spin heme b center, a high-spin heme b center, and a non-heme Fe center. The soluble domain of NorC, NorC* (ΔMet1-Val37) was heterologously expressed in Escherichia coli using expression plasmids harboring the truncated norC gene deleted of its 84 5'-terminal nucleotides. Analogous scission of the N-terminal helix as the membrane anchor took place when the whole norC gene was used.

Tandem and single genes of three membrane-bound nitrate transporters in the nar gene cluster of the moderately halophilic denitrifier, Halomonas halodenitrificans.

We identified the genes encoding the membrane-bound nitrate reductase (Nar) from the moderate halophile, Halomonas halodenitrificans, and examined the structure of the gene cluster. Screening of a H. halodenitrificans genomic DNA library in lambda EMBL3 phage by chromosome walking revealed that the region adjacent to the nor gene cluster encoding nitric oxide (NO) reductase contains three nitrate transporters: tandem narK2 and narK1.

Fates of Cdh23/CDH23 with mutations affecting the cytoplasmic region.

BUS/Idr mice carrying a mutant waltzer allele (vbus) are characterized by splayed hair bundles in inner ear sensory cells, providing a mouse homolog of USH1D/DFNB12. RT-PCR-based screening for the presence of mutations in mouse Cdh23, the gene responsible for the waltzer phenotype, has identified a G>A mutation in the donor splice site of intron 67 (Cdh23:c.9633+1G>A: GenBank AF308939.

Diverse NO reduction by Halomonas halodenitrificans nitric oxide reductase.

Reduction of the four Fe centers is not required to initiate the reaction of the Halomonas halodenitrificans nitric oxide reductase (NOR) based on the facts that NOR in the form that ferric heme b(3) and non-heme iron (Fe(B)) are not bridged and/or the interaction between them is weakened and reversibly binds NO molecules, and that NOR in the form that only heme b(3) is oxidized reacts with NO molecules.

The reversible change in the redox state of type I Cu in Myrothecium verrucaria bilirubin oxidase depending on pH.

The redox state of type I Cu in Myrothecium verrucaria bilirubin oxidase (BO), a multicopper oxidase utilized in the clinical investigation of liver, is an equilibrium state of the oxidized and reduced forms, reflected in the reversible absorption and electron paramagnetic resonance (EPR) spectral changes depending on pH.

Type III Cu mutants of Myrothecium verrucaria bilirubin oxidase.

Type III Cu ligand, His456 and His458, of Myrothecium verrucaria (MT-1) bilirubin oxidases (BO) [EC 1.3.3.