Identification of a copper-repressible C-type heme protein of Methylococcus capsulatus (Bath). A member of a novel group of the bacterial di-heme cytochrome c peroxidase family of proteins.

Genomic sequencing of the methanotrophic bacterium, Methylococcus capsulatus (Bath), revealed an open reading frame (MCA2590) immediately upstream of the previously described mopE gene (MCA2589). Sequence analyses of the deduced amino acid sequence demonstrated that the MCA2590-encoded protein shared significant, but restricted, sequence similarity to the bacterial di-heme cytochrome c peroxidase (BCCP) family of proteins. Two putative C-type heme-binding motifs were predicted, and confirmed by positive heme staining.

Characterization of a prokaryotic haemerythrin from the methanotrophic bacterium Methylococcus capsulatus (Bath).

For a long time, the haemerythrin family of proteins was considered to be restricted to only a few phyla of marine invertebrates. When analysing differential protein expression in the methane-oxidizing bacterium, Methylococcus capsulatus (Bath), grown at a high and low copper-to-biomass ratio, respectively, we identified a putative prokaryotic haemerythrin expressed in high-copper cultures. Haemerythrins are recognized by a conserved sequence motif that provides five histidines and two carboxylate ligands which coordinate two iron atoms.

Genomic insights into methanotrophy: the complete genome sequence of Methylococcus capsulatus (Bath).

Methanotrophs are ubiquitous bacteria that can use the greenhouse gas methane as a sole carbon and energy source for growth, thus playing major roles in global carbon cycles, and in particular, substantially reducing emissions of biologically generated methane to the atmosphere. Despite their importance, and in contrast to organisms that play roles in other major parts of the carbon cycle such as photosynthesis, no genome-level studies have been published on the biology of methanotrophs. We report the first complete genome sequence to our knowledge from an obligate methanotroph, Methylococcus capsulatus (Bath), obtained by the shotgun sequencing approach.

Structural characterization of the fusobacterial non-specific porin FomA suggests a 14-stranded topology, unlike the classical porins.

Native and recombinant FomA proteins were extracted by detergent from the cell envelopes of Fusobacterium nucleatum and Escherichia coli, and purified to near homogeneity by chromatography. Circular dichroism analysis revealed that the FomA protein consists predominantly of beta-sheets, in line with the previously proposed 16-stranded beta-barrel topology model. Results obtained by trypsin treatment of intact cells and cell envelopes of F.