Molecular analysis of an outer membrane protein, MopB, of Methylococcus capsulatus (Bath) and structural comparisons with proteins of the OmpA family.

The gene encoding a major outer membrane protein (MopB) of the methanotroph Methylococcus capsulatus (Bath) was cloned and sequenced. The cloned DNA contained an open reading frame of 1044 bp coding for a 348-amino-acid polypeptide with a 21-amino-acid leader peptide. Comparative sequence analysis of the predicted amino acid sequence revealed that the C-terminal part of MopB possessed sequences that are conserved in the OmpA family of proteins.

Molecular biology and regulation of methane monooxygenase.

Methanotrophs are ubiquitous in the environment and play an important role in mitigating global warming due to methane. They are also potentially interesting for industrial applications such as production of bulk chemicals or bioremediation. The first step in the oxidation of methane is the conversion to methanol by methane monooxygenase, the key enzyme, which exists in two forms: the cytoplasmic, soluble methane monooxygenase (sMMO) and the membrane-bound, particulate methane monooxygenase (pMMO).

Detection of Methane Oxidizing Bacteria in Forest Soil by Monooxygenase PCR Amplification.

Atmospheric methane oxidation by a spruce forest soil from Norway at 15 degrees C was found to be maximal at a depth of ca 7 cm. Examination of the kinetics of this methane oxidation revealed an apparent K(m) of 403.1 nM and a V(max) of 2.

Early-onset Alzheimer disease caused by a new mutation (V717L) in the amyloid precursor protein gene.

Context: Alzheimer disease is the most common form of dementia. Mutations in the genes amyloid precursor protein (APP), presenilin 1(PS1) and presenilin 2(PS2) have been found in early-onset familial forms of Alzheimer disease

Objective: To determine the cause of dementia in a family with early-onset illness.

Design, Setting, And Participants: A family with a history of dementia was referred to the Indiana Alzheimer Disease Center, Indianapolis.

Isolation and characterization of two new methanesulfonic acid-degrading bacterial isolates from a Portuguese soil sample.

Two novel bacterial strains that can utilize methanesulfonic acid as a source of carbon and energy were isolated from a soil sample collected in northern Portugal. Morphological, physiological, biochemical and molecular biological characterization of the two isolates indicate that strain P1 is a pink-pigmented facultative methylotroph belonging to the genus Methylobacterium, while strain P2 is a restricted methylotroph belonging to the genus Hyphomicrobium. Both strains are strictly aerobic, degrade methanesulfonate, and release small quantities of sulfite into the medium.

Regulation of expression of methane monooxygenases by copper ions.

Many methanotrophs contain both a soluble and a particulate methane monooxygenase. A unique metabolic switch, mediated by copper ions, regulates the expression of these enzymes. When the copper-to-biomass ratio of the cell is low, the soluble enzyme is expressed, and when the copper-to-biomass ratio is high, the particulate enzyme is expressed.

Molecular analysis of the pmo (particulate methane monooxygenase) operons from two type II methanotrophs.

The particulate methane monooxygenase gene clusters, pmoCAB, from two representative type II methanotrophs of the alpha-Proteobacteria, Methylosinus trichosporium OB3b and Methylocystis sp. strain M, have been cloned and sequenced. Primer extension experiments revealed that the pmo cluster is probably transcribed from a single transcriptional start site located 300 bp upstream of the start of the first gene, pmoC, for Methylocystis sp.

Stable-isotope probing as a tool in microbial ecology.

Microorganisms are responsible for driving the biogeochemical cycling of elements on Earth. Despite their importance and vast diversity, the taxonomic identity of the microorganisms involved in any specific process has usually been confined to that small fraction of the microbiota that has been isolated and cultivated. The recent coupling of molecular biological methods with stable-isotope abundance in biomarkers has provided a cultivation-independent means of linking the identity of bacteria with their function in the environment.

Fluorescent oligonucleotide rDNA probes for specific detection of methane oxidising bacteria.

Oligonucleotide probes targeting the 16S rRNA of distinct phylogenetic groups of methanotrophs were designed for the in situ detection of these organisms. A probe, MG-64, detected specifically type I methanotrophs, while probes MA-221 and MA-621, detected type II methanotrophs in whole cell hybridisations. A probe Mc1029 was also designed which targeted only organisms from the Methylococcus genus after whole cell hybridisations.

The relationship among demographic variables, professionalism, and level of involvement in a state occupational therapy association.

Research on professional occupations has defined varying criteria that an occupation must meet to be considered a profession. Involvement by the members in their professional organization is a recurrent theme. A questionnaire consisting of Hall's Occupational Inventory, an involvement scale, and a demographic survey was used to determine the relationship among three factors of the Indiana Occupational Therapy Association members: (a) demographics, (b) professional attributes, and (c) involvement in a state occupational therapy organization.

Tau gene mutation G389R causes a tauopathy with abundant pick body-like inclusions and axonal deposits.

Exonic and intronic mutations in Tau cause familial neurodegenerative syndromes characterized by frontotemporal dementia and dysfunction of multiple cortical and subcortical circuits. Here we describe a G389R mutation in exon 13 of Tau. When 38 years old, the proband presented with progressive aphasia and memory disturbance, followed by apathy, indifference, and hyperphagia.

Molecular Ecological Analysis of Methanogens and Methanotrophs in Blanket Bog Peat.

Abstract Methane production and methane oxidation potential were measured in a 30 cm peat core from the Moorhouse Nature Reserve, UK. The distribution of known groups of methanogens and methane oxidizing bacteria throughout this peat core was assessed. Using 16S rRNA gene retrieval and functional gene probing with genes encoding key proteins in methane oxidation and methanogenesis, several major groups of microorganisms were detected.

Desulfonation of propanesulfonic acid by comamonas acidovorans strain P53: evidence for an alkanesulfonate sulfonatase and an atypical sulfite dehydrogenase.

Evidence is presented for the presence in propanesulfonate-grown Comamonas acidovorans strain P53 of a cytoplasmically located sulfonatase that does not sediment at 100,000 x g. This enzyme catalysed the sulfonate-dependent oxidation of NADH or NADPH, indicating a monooxygenase that effects the addition of molecular oxygen to C(3)-C(6) 1-alkanesulfonates. Enzyme activity was proportional to protein concentration only above approximately 2 mg cytoplasmic fraction protein ml(-1), suggesting that the sulfonatase is a multicomponent enzyme, possibly comparable with methanesulfonate monooxygenase.

Microbial metabolism of methanesulfonic acid.

Methanesulfonic acid is a very stable strong acid and a key intermediate in the biogeochemical cycling of sulfur. It is formed in megatonne quantities in the atmosphere from the chemical oxidation of atmospheric dimethyl sulfide (most of which is of biogenic origin) and deposited on the Earth in rain and snow, and by dry deposition. Methanesulfonate is used by diverse aerobic bacteria as a source of sulfur for growth, but is not known to be used by anaerobes either as a sulfur source, a fermentation substrate, an electron acceptor, or as a methanogenic substrate.

An olfactory sensory neuron line, odora, properly targets olfactory proteins and responds to odorants.

The site for interactions between the nervous system and much of the chemical world is in the olfactory sensory neuron (OSN). Odorant receptor proteins (ORPs) are postulated to mediate these interactions. However, the function of most ORPs has not been demonstrated in vivo or in vitro.

Characterization of methanotrophic bacterial populations in soils showing atmospheric methane uptake.

The global methane cycle includes both terrestrial and atmospheric processes and may contribute to feedback regulation of the climate. Most oxic soils are a net sink for methane, and these soils consume approximately 20 to 60 Tg of methane per year. The soil sink for atmospheric methane is microbially mediated and sensitive to disturbance.

A mutation at codon 279 (N279K) in exon 10 of the Tau gene causes a tauopathy with dementia and supranuclear palsy.

Recently intronic and exonic mutations in the Tau gene have been found to be associated with familial neurodegenerative syndromes characterized not only by a predominantly frontotemporal dementia but also by the presence of neurological signs consistent with the dysfunction of multiple subcortical neuronal circuitries. Among families, the symptomatology appears to vary in quality and severity in relation to the specific Tau gene mutation and often may include parkinsonism, supranuclear palsies, and/or myoclonus, in addition to dementia. We carried out molecular genetic and neuropathological studies on two patients from a French family presenting, early in their fifth decade, a cognitive impairment and supranuclear palsy followed by an akinetic rigid syndrome and dementia.

Structure of tau exon 10 splicing regulatory element RNA and destabilization by mutations of frontotemporal dementia and parkinsonism linked to chromosome 17.

Coding region and intronic mutations in the tau gene cause frontotemporal dementia and parkinsonism linked to chromosome 17. Intronic mutations and some missense mutations increase splicing in of exon 10, leading to an increased ratio of four-repeat to three-repeat tau isoforms. Secondary structure predictions have led to the proposal that intronic mutations and one missense mutation destabilize a putative RNA stem-loop structure located close to the splice-donor site of the intron after exon 10.

Frontotemporal dementia and corticobasal degeneration in a family with a P301S mutation in tau.

The tau gene has been found to be the locus of dementia with rigidity linked to chromosome 17. Exonic and intronic mutations have been described in a number of families. Here we describe a P301S mutation in exon 10 of the tau gene in a new family.

Linear alkanesulfonates as carbon and energy sources for gram-positive and gram-negative bacteria.

Several bacteria from soil and rainwater samples were enriched and isolated with propanesulfonate or butanesulfonate as sole carbon and energy source. Most of the strains isolated utilized nonsubstituted alkanesulfonates with a chain length of C3-C6 and the substituted sulfonates taurine and isethionate as carbon and energy source. A gram-positive isolate, P40, and a gram-negative isolate, P53, were characterized in more detail.

Heterologous expression of soluble methane monooxygenase genes in methanotrophs containing only particulate methane monooxygenase.

The methanotrophs Methylococcus capsulatus (Bath) and Methylosinus trichosporium OB3b contain particulate methane monooxygenase (pMMO) and soluble methane monooxygenase (sMMO) genes. Other methanotrophs such as Methylomicrobium album BG8 and Methylocystis parvus OBBP contain only pMMO genes. Although molecular genetic techniques are poorly developed in methanotrophs, sMMO genes were expressed in methanotrophs normally containing only pMMO genes.

Tau pathology in a family with dementia and a P301L mutation in tau.

Familial forms of frontotemporal dementia and parkinsonism linked to chromosome 17 (FTDP-17) have recently been associated with coding region and intronic mutations in the tau gene. Here we report our findings on 2 affected siblings from a family with early-onset dementia, characterized by extensive tau pathology and a Pro to Leu mutation at codon 301 of tau. The proband, a 55-year-old woman, and her 63-year-old brother died after a progressive dementing illness clinically diagnosed as Alzheimer disease.

Heterologous expression of alkene monooxygenase from Rhodococcus rhodochrous B-276.

Alkene monooxygenase (AMO) from Rhodococcus rhodochrous (formerly Nocardia corallina) B-276 is a three-component enzyme system encoded by the four-gene operon amoABCD. AMO catalyses the stereoselective epoxygenation of aliphatic alkenes, yielding primarily R enantiomers. The presumed site of alkene oxygenation is a dinuclear iron centre similar to that in the soluble methane monooxygenases of methanotrophic bacteria, to which AMO exhibits a significant degree of amino acid sequence identity.