Identification and Characterization of a Cryptic Bifunctional Type I Diterpene Synthase Involved in Talaronoid Biosynthesis from a Marine-Derived Fungus.

We report the identification of the biosynthetic cluster from the marine-derived fungus and the in vivo characterization of a cryptic type I diterpene synthase. The heterologous expression of the bifunctional terpene synthase led to the discovery of a diterpene backbone, talarodiene, harboring a benzo[]cyclopenta[]cyclooctane tricyclic fused ring system. The conversion of geranylgeranyl diphosphate to talarodiene was investigated using C-labeling studies, and stable isotope tracer experiments showed the biotransformation of talarodiene into talaronoid C.

Molecular Diversity of Terpene Synthases in the Liverwort Marchantia polymorpha.

Marchantia polymorpha is a basal terrestrial land plant, which like most liverworts accumulates structurally diverse terpenes believed to serve in deterring disease and herbivory. Previous studies have suggested that the mevalonate and methylerythritol phosphate pathways, present in evolutionarily diverged plants, are also operative in liverworts. However, the genes and enzymes responsible for the chemical diversity of terpenes have yet to be described.

Mapping a kingdom-specific functional domain of squalene synthase.

Squalene synthase catalyzes the first committed step in sterol biosynthesis and consists of both an amino-terminal catalytic domain and a carboxy-terminal domain tethering the enzyme to the ER membrane. While the overall architecture of this enzyme is identical in eukaryotes, it was previously shown that plant and animal genes cannot complement a squalene synthase knockout mutation in yeast unless the carboxy-terminal domain is swapped for one of fungal origin. This implied a unique component of the fungal carboxy-terminal domain was responsible for the complementation phenotype.

Experimental Genome-Wide Determination of RNA Polyadenylation in Chlamydomonas reinhardtii.

The polyadenylation of RNA is a near-universal feature of RNA metabolism in eukaryotes. This process has been studied in the model alga Chlamydomonas reinhardtii using low-throughput (gene-by-gene) and high-throughput (transcriptome sequencing) approaches that recovered poly(A)-containing sequence tags which revealed interesting features of this critical process in Chlamydomonas. In this study, RNA polyadenylation has been studied using the so-called Poly(A) Tag Sequencing (PAT-Seq) approach.

HIV pre-test information, discussion or counselling? A review of guidance relevant to the WHO European Region.

In the context of a shift from exceptionalism to normalisation, this study examines recommendations/evidence in current pan-European/global guidelines regarding pre-test HIV testing and counselling practices in health care settings. It also reviews new research not yet included in guidelines. There is consensus that verbal informed consent must be gained prior to testing, individually, in private, confidentially, in the presence of a health care provider.

Production, purification, and assay of recombinant proteins for in vitro biochemical analyses of the plant polyadenylation complex.

In the post-genomic era where gene sequences are available for many organisms, attention has shifted from DNA to the workhorses of the cell-RNA and protein. A number of proteins, as recent studies indicate, seem to possess RNA-binding and RNA cleavage activities. In order to understand the events that comprise RNA processing such as splicing, 3' end processing, and even RNA turnover, well established methods are necessary.

Now playing: farnesol in the biofilm.

The evolutionary pathway of specialized metabolism often takes unexpected, perplexing turns. In this issue of Chemistry & Biology, Feng and coworkers provide evidence for a unique phosphatase whose enzymatic product plays a critical role in biofilm formation in Bacillus subtilis.

Structure-function mapping of key determinants for hydrocarbon biosynthesis by squalene and squalene synthase-like enzymes from the green alga Botryococcus braunii race B.

Squalene and botryococcene are branched-chain, triterpene compounds that arise from the head-to-head condensation of two molecules of farnesyl diphosphate to yield 1'-1 and 1'-3 linkages, respectively. The enzymes that catalyze their formation have attracted considerable interest from the medical field as potential drug targets and the renewable energy sector for metabolic engineering efforts. Recently, the enzymes responsible for botryococcene and squalene biosynthesis in the green alga Botryococcus braunii race B were characterized.

'Mobile men with money': HIV prevention and the erasure of difference.

Mobile Men with Money is one of the latest risk categories to enter into HIV prevention discourse. Used in countries in Asia, the Pacific and Africa, it refers to diverse groups of men (e.g.

Functional identification of triterpene methyltransferases from Botryococcus braunii race B.

Botryococcus braunii race B is a colony-forming, green algae that accumulates triterpene oils in excess of 30% of its dry weight. The composition of the triterpene oils is dominated by dimethylated to tetramethylated forms of botryococcene and squalene. Although unusual mechanisms for the biosynthesis of botryococcene and squalene were recently described, the enzyme(s) responsible for decorating these triterpene scaffolds with methyl substituents were unknown.

Young people and sexual agency in rural Uganda.

This paper offers an analysis of young people's sexual agency in rural Uganda. Drawing on definitions of agency from within the international development literature, it focuses on: decision-making processes leading to young people's involvement in relationships; actions undertaken to maintain 'secret' relationships in contexts where young people's sexual agency is generally prohibited; transactional and gendered negotiations between young people involved within a relationship; and a range of outcomes arising from young people's sexual activity. An understanding of the dynamics and temporal nature of young people's sexual agency, and the consequences that follow from it, challenges the widely held view that young people do not know what they are doing in relation to their sexual health.

The Arabidopsis ortholog of the 77 kDa subunit of the cleavage stimulatory factor (AtCstF-77) involved in mRNA polyadenylation is an RNA-binding protein.

The 77 kDa subunit of the polyadenylation cleavage stimulation factor (CstF77) is important in messenger RNA 3' end processing. Previously, we demonstrated that AtCstF77 interacts with AtCPSF30, the Arabidopsis ortholog of the 30 kDa subunit of the Cleavage and Polyadenylation Specificity Factor. In further dissecting this interaction, it was found that the C-terminus of AtCstF77 interacts with AtCPSF30.

Synthesis and characterization of covalently linked single-stranded DNA oligonucleotide-dendron conjugates.

A solution-phase synthesis and characterization of covalent DNA-dendron conjugates is presented. Thiol-terminated 12-base oligonucleotides were added to second- and third-generation triazine-based dendrons via thiol/disulfide exchange chemistry. Single-stranded DNA oligonucleotides were successfully attached to dendrons at the core, the periphery, and both.

Catalytic double-bond metathesis without the transition metal.

Iminophosphoranes of the type X(3)P=NR (X = Cl, pyrrolyl; R = alkyl, aryl) catalytically metathesize C=N bonds of carbodiimides via an addition/elimination mechanism that, despite the lack of d orbital participation in P-N bonding, conserves the key features of metal-catalyzed olefin metathesis. Diazaphosphetidine intermediates, produced by the formal [2 + 2] addition of carbodiimides to the P=N bond, have been isolated and characterized. All phosphorus-containing species in the complex catalytic reaction mixtures have been identified and their origins explained.