Characterization of the intracellular polyphosphate granules of the phototrophic green sulfur bacterium Chlorobaculum tepidum.

The ability to generate polyphosphate (polyP) granules is important for survival for bacteria during resistance to diverse environmental stresses, however the genesis of polyP granules is poorly understood. Chlorobaculum tepidum (Cba tepidum) is a thermophilic green sulfur anoxygenic phototrophic bacterium which uses reduced sulfur compounds as electron donors. The presence of electron rich granules inside the Cba tepidum was reported, but no further information was provided.

The synergy between the PscC subunits for electron transfer to the P special pair in Chlorobaculum tepidum.

The primary photochemical reaction of photosynthesis in green sulfur bacteria occurs in the homodimer PscA core proteins by a special chlorophyll pair. The light induced excited state of the special pair producing P is rapidly reduced by electron transfer from one of the two PscC subunits. Molecular dynamics (MD) simulations are combined with bioinformatic tools herein to provide structural and dynamic insight into the complex between the two PscA core proteins and the two PscC subunits.

Production of Polyhydroxybutyrate by Genetically Modified sp. phDV1: A Comparative Study of Utilizing Wine Industry Waste as a Carbon Source.

sp. phDV1 is a polyhydroxyalkanoate (PHA) producer. The presence of the endogenous PHA depolymerase (phaZ) responsible for the degradation of the intracellular PHA is one of the main shortages in the bacterial production of PHA.

Insights into the sulfur metabolism of Chlorobaculum tepidum by label-free quantitative proteomics.

Chlorobaculum tepidum is an anaerobic green sulfur bacterium which oxidizes sulfide, elemental sulfur, and thiosulfate for photosynthetic growth. It can also oxidize sulfide to produce extracellular S globules, which can be further oxidized to sulfate and used as an electron donor. Here, we performed label-free quantitative proteomics on total cell lysates prepared from different metabolic states, including a sulfur production state (10 h post-incubation [PI]), the beginning of sulfur consumption (20 h PI), and the end of sulfur consumption (40 h PI), respectively.

Cryo-EM structure of the whole photosynthetic reaction center apparatus from the green sulfur bacterium .

Light energy absorption and transfer are very important processes in photosynthesis. In green sulfur bacteria light is absorbed primarily by the chlorosomes and its energy is transferred via the Fenna-Matthews-Olson (FMO) proteins to a homodimeric reaction center (RC). Here, we report the cryogenic electron microscopic structure of the intact FMO-RC apparatus from at 2.

Rational engineering of ()-selective amine transaminase for the acceptance of bulky substrates.

Despite the plethora of information on ()-selective amine transaminases, the ()-selective ones are still not well-studied; only a few structures are known to date, and their substrate scope is limited, apart from a few stellar works in the field. Herein, the structure of ()-selective amine transaminase is elucidated to facilitate engineering towards variants active on bulkier substrates. The V37A variant exhibited increased activity towards 1-phenylpropylamine and to activity against 1-butylamine.

Polyhydroxyalkanoate (PHA) Production in sp. phDV1 Strain Grown on Phenol as Carbon Sources.

strains have a variety of potential uses in bioremediation and biosynthesis of biodegradable plastics. sp. strain phDV1, a Gram-negative phenol degrading bacterium, has been found to utilize monocyclic aromatic compounds as sole carbon source via the -cleavage pathway.

Expression, purification and characterization of the IcmG and IcmK proteins of the type IVB secretion system from Coxiella burnetii.

Coxiella burnetii, the causative agent of Q fever, is an intracellular bacterial pathogen. Studies on Coxiella have shown that a type IVB secretion system (T4BSS) contributes to the establishment of the infection by transferring protein molecules. In this report, we focus on two core proteins of the Coxiella T4BSS, namely the IcmG/DotF protein (CBU_1626) and the IcmK/DotH protein (CBU_1628).

Proteomic Characterization of the Pseudomonas sp. Strain phDV1 Response to Monocyclic Aromatic Compounds.

The degradation of aromatic compounds comprises an important step in the removal of pollutants and re-utilization of plastics and other non-biological polymers. Here, Pseudomonas sp. strain phDV1, a gram-negative bacterium that is selected for its ability to degrade aromatic compounds is studied.

In the Search of Potential Serodiagnostic Proteins to Discriminate Between Acute and Chronic Q Fever in Humans. Some Promising Outcomes.

is the agent that causes acute and chronic Q fever infections in humans. Although the isolates studied so far have shown that the two forms of the disease differ in virulence potential thus, implying a variance in their proteomic profile, the methods used do not deliver enough discriminatory capability and often, human infections may be mis-diagnosed. The current study adds further knowledge to the results that we have already published on the Coxiella outer membrane protein 1 (Com1).

Proteome Analysis of Enriched Heterocysts from Two Hydrogenase Mutants from Anabaena sp. PCC 7120.

Cyanobacteria are oxygenic photosynthetic prokaryotes and play a crucial role in the Earth's carbon and nitrogen cycles. The photoautotrophic cyanobacterium Anabaena sp. PCC 7120 has the ability to fix atmospheric nitrogen in heterocysts and produce hydrogen as a byproduct through a nitrogenase.

Complete Genome Sequence of sp. Strain phDV1, an Isolate Capable of Efficient Degradation of Aromatic Hydrocarbons.

Pseudomonas sp. strain phDV1 is a Gram-negative bacterium capable of degrading aromatic hydrocarbons. Here, we present the complete genome sequence of this strain, which consists of 4,727,682 bp, with a 62.

Proteome Changes Induced by Imatinib and Novel Imatinib Derivatives in K562 Human Chronic Myeloid Leukemia Cells.

Imatinib mesylate is the leading compound to treat chronic myeloid leukemia (CML) and other cancers, through its inhibition of Bcr-Abl tyrosine kinases. However, resistance to imatinib develops frequently, particularly in late-stage disease and has necessitated the development of new Bcr-Abl inhibitors. The synthesis of a new series of phenylaminopyrimidines, structurally related to imatinib, showed large interest since the introduction of nilotinib.

The ultrastructure of Chlorobaculum tepidum revealed by cryo-electron tomography.

Chlorobaculum (Cba) tepidum is a green sulfur bacterium that oxidizes sulfide, elemental sulfur, and thiosulfate for photosynthetic growth. As other anoxygenic green photosynthetic bacteria, Cba tepidum synthesizes bacteriochlorophylls for the assembly of a large light-harvesting antenna structure, the chlorosome. Chlorosomes are sac-like structures that are connected to the reaction centers in the cytoplasmic membrane through the BChl α-containing Fenna-Matthews-Olson protein.

Proteome studies of bacterial antibiotic resistance mechanisms.

Ever since antibiotics were used to help humanity battle infectious diseases, microorganisms straight away fought back. Antibiotic resistance mechanisms indeed provide microbes with possibilities to by-pass and survive the action of antibiotic drugs. Several methods have been employed to identify these microbial resistance mechanisms in an ongoing effort to reduce the steadily increasing number of treatment failures due to multi-drug-resistant microbes.

The contribution of proteomics towards deciphering the enigma of Coxiella burnetii.

Coxiella burnetii, the causative agent of Q fever, is an intracellular bacterium and a potential weapon for bioterrorism. The widespread throughout the world, zoonosis is manifested clinically as a self-limited febrile illness, as pneumonia (acute Q fever) or as a chronic illness with endocarditis being its major complication. The recent Netherlands Q fever outbreak has driven the bacterium from a relatively cryptic, underappreciated, "niche" microorganism on the sideline of bacteriology, to one of possibly great impact on public health.

Study of the whole cell lysate of two Coxiella burnetii strains using N-terminomics.

The etiological agent of Q fever is Coxiella burnetii , an obligate intracellular Gram-negative bacterium and the only bacterium known to date that survives and replicates within a vacuole of phagolysosomal characteristics. In humans, Q fever is characterized by a wide spectrum of clinical manifestations. Of note is that genetic diversity among C.

Quantitative proteome profiling of C. burnetii under tetracycline stress conditions.

The recommended antibiotic regimen against Coxiella burnetii, the etiological agent of Q fever, is based on a semi-synthetic, second-generation tetracycline, doxycycline. Here, we report on the comparison of the proteomes of a C. burnetii reference strain either cultured under control conditions or under tetracycline stress conditions.

Investigation of rifampicin resistance mechanisms in Brucella abortus using MS-driven comparative proteomics.

Mutations in the rpoB gene have already been shown to contribute to rifampicin resistance in many bacterial strains including Brucella species. Resistance against this antibiotic easily occurs and resistant strains have already been detected in human samples. We here present the first research project that combines proteomic, genomic, and microbiological analysis to investigate rifampicin resistance in an in vitro developed rifampicin resistant strain of Brucella abortus 2308.

Proteome profiling of the green sulfur bacterium Chlorobaculum tepidum by N-terminal proteomics.

In this study, we performed the first large-scale identification of N-terminal peptides from the green sulfur bacterium Chlorobaculum tepidum. Combined fractional diagonal chromatography (COFRADIC) was used to isolate protein N-terminal peptides from three different proteome preparations, and following LC-MS/MS analysis, over 621 different proteins were identified by their N-terminal peptides. Our data constitute the largest data set currently available for protein N-termini of prokaryotic photosynthetic organisms.

Unraveling persistent host cell infection with Coxiella burnetii by quantitative proteomics.

The interaction between the immune system and invading bacteria is sufficient to eradicate microorganisms for the majority of bacterial infections, but suppression of the microbicidal response leads to reactivation or chronic evolution of infections and to bacterial persistence. To identify the cellular pathways affected by bacterial persistence, we applied the MS-driven combined fractional diagonal chromatography (COFRADIC) proteomics technique for a comparative study of protein expression in the C. burnetii strains Nine Mile (NM) and its respective strain (NMper) isolated from 18 months persistently infected cell cultures.

The chlorosome of Chlorobaculum tepidum: size, mass and protein composition revealed by electron microscopy, dynamic light scattering and mass spectrometry-driven proteomics.

Chlorosomes, the antenna complexes of green bacteria, are unique antenna systems in which pigments are organized in aggregates. Studies on isolated chlorosomes from Chlorobaculum tepidum based on SDS-PAGE, immunoblotting and molecular biology have revealed that they contain ten chlorosomal proteins, but no comprehensive information is available about the protein composition of the entire organelle. To extend these studies, chlorosomes were isolated from C.

A proteomic approach to investigate the differential antigenic profile of two Coxiella burnetii strains.

Q fever is a widespread zoonosis caused by Coxiella burnetii, an obligate intracellular Gram-negative bacterium. Current diagnostics of Q fever is based on serological testing of patient serum. Biological distinction among C.

Identification of potentially involved proteins in levofloxacin resistance mechanisms in Coxiella burnetii.

The etiological agent of Q fever, Coxiella burnetii, is an obligate intracellular bacterium that multiplies within a phagosome-like parasitophorous vacuole. Fluoroquinolones have been used as an alternative therapy for Q fever. Resistance to fluoroquinolones can arise via several mechanisms utilized by pathogens to avoid killing.

Membrane proteome of the green sulfur bacterium Chlorobium tepidum (syn. Chlorobaculum tepidum) analyzed by gel-based and gel-free methods.

Chlorobium tepidum is a Gram-negative bacterium of the green sulfur phylum (Chlorobia). Chlorobia are obligate anaerobic photolithoautotrophs that are widely distributed in aquatic environments where anoxic layers containing reduced sulfur compounds are exposed to light. The envelope of C.