Identification and Characterization of Two Aryl Sulfotransferases from Deep-Sea Marine Fungi and Their Implications in the Sulfation of Secondary Metabolites.

Sulfation plays a critical role in the biosynthesis of small molecules, regulatory mechanisms such as hormone signaling, and detoxification processes (phase II enzymes). The sulfation reaction is catalyzed by a broad family of enzymes known as sulfotransferases (SULTs), which have been extensively studied in animals due to their medical importance, but also in plant key processes. Despite the identification of some sulfated metabolites in fungi, the mechanisms underlying fungal sulfation remain largely unknown.

Heterologous Expression and Biochemical Characterization of a New Chloroperoxidase Isolated from the Deep-Sea Hydrothermal Vent Black Yeast Hortaea werneckii UBOCC-A-208029.

The initiation of this study relies on a targeted genome-mining approach to highlight the presence of a putative vanadium-dependent haloperoxidase-encoding gene in the deep-sea hydrothermal vent fungus Hortaea werneckii UBOCC-A-208029. To date, only three fungal vanadium-dependent haloperoxidases have been described, one from the terrestrial species Curvularia inaequalis, one from the fungal plant pathogen Botrytis cinerea, and one from a marine derived isolate identified as Alternaria didymospora. In this study, we describe a new vanadium chloroperoxidase from the black yeast H.

Deciphering interactions between the marine dinoflagellate Prorocentrum lima and the fungus Aspergillus pseudoglaucus.

The comprehension of microbial interactions is one of the key challenges in marine microbial ecology. This study focused on exploring chemical interactions between the toxic dinoflagellate Prorocentrum lima and a filamentous fungal species, Aspergillus pseudoglaucus, which has been isolated from the microalgal culture. Such interspecies interactions are expected to occur even though they were rarely studied.

Halogenation in Fungi: What Do We Know and What Remains to Be Discovered?

In nature, living organisms produce a wide variety of specialized metabolites to perform many biological functions. Among these specialized metabolites, some carry halogen atoms on their structure, which can modify their chemical characteristics. Research into this type of molecule has focused on how organisms incorporate these atoms into specialized metabolites.

Pentadecaibins I-V: 15-Residue Peptaibols Produced by a Marine-Derived sp. of the Clade.

In the course of investigations on peptaibol chemodiversity from marine-derived spp., five new 15-residue peptaibols named pentadecaibins I-V (-) were isolated from the solid culture of the strain sp. MMS1255 belonging to the species complex.

Comparative genomics applied to Mucor species with different lifestyles.

Background: Despite a growing number of investigations on early diverging fungi, the corresponding lineages have not been as extensively characterized as Ascomycota or Basidiomycota ones. The Mucor genus, pertaining to one of these lineages is not an exception. To this date, a restricted number of Mucor annotated genomes is publicly available and mainly correspond to the reference species, Mucor circinelloides, and to medically relevant species.

Comparative analysis of five Mucor species transcriptomes.

Mucor species belong to the Mucorales order within the Mucoromycota phylum, an early diverging fungal lineage. Although Mucor species are often ubiquitous some species have been reported to specifically occur in certain ecological niches. In this study, similarities and differences of a representative set of Mucor species with contrasted lifestyles were investigated at the transcriptome level.

Penicillium roqueforti PR toxin gene cluster characterization.

PR toxin is a well-known isoprenoid mycotoxin almost solely produced by Penicillium roqueforti after growth on food or animal feed. This mycotoxin has been described as the most toxic produced by this species. In this study, an in silico analysis allowed identifying for the first time a 22.

Identification and quantification of antifungal compounds produced by lactic acid bacteria and propionibacteria.

Fungal growth in bakery products represents the most frequent cause of spoilage and leads to economic losses for industrials and consumers. Bacteria, such as lactic acid bacteria and propionibacteria, are commonly known to play an active role in preservation of fermented food, producing a large range of antifungal metabolites. In a previous study (Le Lay et al.

Deep Subseafloor Fungi as an Untapped Reservoir of Amphipathic Antimicrobial Compounds.

The evolving global threat of antimicrobial resistance requires a deep renewal of the antibiotic arsenal including the isolation and characterization of new drugs. Underexplored marine ecosystems may represent an untapped reservoir of novel bioactive molecules. Deep-sea fungi isolated from a record-depth sediment core of almost 2000 m below the seafloor were investigated for antimicrobial activities.

Species richness and adaptation of marine fungi from deep-subseafloor sediments.

The fungal kingdom is replete with unique adaptive capacities that allow fungi to colonize a wide variety of habitats, ranging from marine habitats to freshwater and terrestrial habitats. The diversity, importance, and ecological roles of marine fungi have recently been highlighted in deep-subsurface sediments using molecular methods. Fungi in the deep-marine subsurface may be specifically adapted to life in the deep biosphere, but this can be demonstrated only using culture-based analyses.

The Vanadium Iodoperoxidase from the marine flavobacteriaceae species Zobellia galactanivorans reveals novel molecular and evolutionary features of halide specificity in the vanadium haloperoxidase enzyme family.

Vanadium haloperoxidases (VHPO) are key enzymes that oxidize halides and are involved in the biosynthesis of organo-halogens. Until now, only chloroperoxidases (VCPO) and bromoperoxidases (VBPO) have been characterized structurally, mainly from eukaryotic species. Three putative VHPO genes were predicted in the genome of the flavobacterium Zobellia galactanivorans, a marine bacterium associated with macroalgae.

Discovery of a novel iota carrageenan sulfatase isolated from the marine bacterium Pseudoalteromonas carrageenovora.

Carrageenans are sulfated polysaccharides extracted from the cell wall of some marine red algae. These polysaccharides are widely used as gelling, stabilizing, and viscosifying agents in the food and pharmaceutical industries. Since the rheological properties of these polysaccharides depend on their sulfate content, we screened several isolated marine bacteria for carrageenan specific sulfatase activity, in the aim of developing enzymatic bioconversion of carrageenans.

Structure/function analysis of a type iii polyketide synthase in the brown alga Ectocarpus siliculosus reveals a biochemical pathway in phlorotannin monomer biosynthesis.

Brown algal phlorotannins are structural analogs of condensed tannins in terrestrial plants and, like plant phenols, they have numerous biological functions. Despite their importance in brown algae, phlorotannin biosynthetic pathways have been poorly characterized at the molecular level. We found that a predicted type III polyketide synthase in the genome of the brown alga Ectocarpus siliculosus, PKS1, catalyzes a major step in the biosynthetic pathway of phlorotannins (i.

A new method to identify flanking sequence tags in chlamydomonas using 3'-RACE.

Background: The green alga Chlamydomonas reinhardtii, although a premier model organism in biology, still lacks extensive insertion mutant libraries with well-identified Flanking Sequence Tags (FSTs). Rapid and efficient methods are needed for FST retrieval.

Results: Here, we present a novel method to identify FSTs in insertional mutants of Chlamydomonas.

Novel shuttle markers for nuclear transformation of the green alga Chlamydomonas reinhardtii.

The green alga Chlamydomonas reinhardtii today is a premier model organism for the study of green algae and plants. Yet the efficient engineering of its nuclear genome requires development of new antibiotic resistance markers. We have recoded, based on codon usage in the nuclear genome, the AadA marker that has been used previously for chloroplast transformation.

Structure and function of a novel endonuclease acting on branched DNA substrates.

We show that Pyrococcus abyssi PAB2263 (dubbed NucS (nuclease for ss DNA) is a novel archaeal endonuclease that interacts with the replication clamp PCNA. Structural determination of P. abyssi NucS revealed a two-domain dumbbell-like structure that in overall does not resemble any known protein structure.

The structure of an archaeal homodimeric ligase which has RNA circularization activity.

The genome of Pyrococcus abyssi contains two open reading frames encoding proteins which had been previously predicted to be DNA ligases, Pab2002 and Pab1020. We show that while the former is indeed a DNA ligase, Pab1020 had no effect on the substrate deoxyoligo-ribonucleotides tested. Instead, Pab1020 catalyzes the nucleotidylation of oligo-ribonucleotides in an ATP-dependent reaction, suggesting that it is an RNA ligase.

A novel proteomic approach identifies new interaction partners for proliferating cell nuclear antigen.

During DNA replication and repair, many proteins bind to and dissociate in a highly specific and ordered manner from proliferating cell nuclear antigen (PCNA). We describe a combined approach of in silico searches at the genome level and combinatorial peptide synthesis to investigate the binding properties of hundreds of short PCNA-interacting peptides (PIP-peptides) to archaeal and eukaryal PCNAs. Biological relevance of our combined approach was demonstrated by identification an inactive complex of Pyrococcus abyssi ribonuclease HII with PCNA.

Crystallization and preliminary X-ray analysis of a RecB-family nuclease from the archaeon Pyrococcus abyssi.

Nucleases are required to process and repair DNA damage in living cells. One of the best studied nucleases is the RecB protein, which functions in Escherichia coli as a component of the RecBCD enzyme complex that amends double-strand breaks in DNA. Although archaea do not contain the RecBCD complex, a RecB-like nuclease from Pyrococcus abyssi has been cloned, expressed and purified.