Interactions among the A and T Units of an ECF-Type Biotin Transporter Analyzed by Site-Specific Crosslinking

Energy-coupling factor (ECF) transporters are a huge group of micronutrient importers in prokaryotes. They are composed of a substrate-specific transmembrane protein (S component) and a module consisting of a moderately conserved transmembrane protein (T component) and two ABC ATPase domains (A components). Modules of A and T units may be dedicated to a specific S component or shared by many different S units in an organism. The mode of subunit interactions in ECF transporters is largely unknown. BioMNY, the focus of the present study, is a biotin transporter with a dedicated AT module. It consists of the S unit BioY, the A unit BioM and the T unit BioN. Like all T units, BioN contains two three-amino-acid signatures with a central Arg residue in a cytoplasmic helical region. Our previous work had demonstrated a central role of the two motifs in T units for stability and function of BioMNY and other ECF transporters. Here we show by site-specific crosslinking of pairs of mono-cysteine variants that the Ala-Arg-Ser and Ala-Arg-Gly signatures in BioN are coupling sites to the BioM ATPases. Analysis of 64 BioN-BioM pairs uncovered interactions of both signatures predominantly with a segment of ∼13 amino acid residues C-terminal of the Q loop of BioM. Our results further demonstrate that portions of all BioN variants with single Cys residues in the two signatures are crosslinked to homodimers. This finding may point to a dimeric architecture of the T unit in BioMNY complexes

COVID-19, systemic crisis, and possible implications for the wild meat trade in sub-Saharan Africa

Wild animals play an integral and complex role in the economies and ecologies of many countries across the globe, including those of West and Central Africa, the focus of this policy perspective. The trade in wild meat, and its role in diets, have been brought into focus as a consequence of discussions over the origins of COVID-19. As a result, there have been calls for the closure of China’s “wet markets”; greater scrutiny of the wildlife trade in general; and a spotlight has been placed on the potential risks posed by growing human populations and shrinking natural habitats for animal to human transmission of zoonotic diseases. However, to date there has been little attention given to what the consequences of the COVID-19 economic shock may be for the wildlife trade; the people who rely on it for their livelihoods; and the wildlife that is exploited. In this policy perspective, we argue that the links between the COVID-19 pandemic, rural livelihoods and wildlife are likely to be more complex, more nuanced, and more far-reaching, than is represented in the literature to date. We develop a causal model that tracks the likely implications for the wild meat trade of the systemic crisis triggered by COVID-19. We focus on the resulting economic shockwave, as manifested in the collapse in global demand for commodities such as oil, and international tourism services, and what this may mean for local African economies and livelihoods. We trace the shockwave through to the consequences for the use of, and demand for, wild meats as households respond to these changes. We suggest that understanding and predicting the complex dynamics of wild meat use requires increased collaboration between environmental and resource economics and the ecological and conservation sciences

Cartographie hydrogéomorphologique et paléochenaux fluviatiles en milieux profondément modifiés par les sociétés. L'exemple du port fluvial antique d'Aquilée dans la plaine du Frioul (Italie septentrionale, Adriatique)»: Actes du Colloque de Metz 2004 « Spatialisation et cartographie en hydrologie »

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Relationship between volatile compounds and consumer-based sensory characteristics of bacon smoked with different brazilian woods

Bacon is a product made from pork meat that is subjected to curing, drying, and smoking. Researchers aim to associate the worldwide high-acceptance of such a product with the sensory and chemical properties of bacon. In this context, the objective of the present study was to characterize bacon samples smoked with different woods from reforestation using chemical and sensory methodologies, which were subsequently correlated by means of statistical multi-block analysis. Volatile compounds (VCs) of the smoked bacons were studied using solid-phase microextraction (SPME) coupled with gas chromatography-mass spectrometry (GC-MS), and the consumer sensory perception was explored by the Napping technique. VCs were identified in smoked samples, which triggered sensory attributes related to odor, flavor, and texture, such as "smoky flavor", "salty taste", "pleasant taste", "woodsy flavor", and "hard texture". Multi-block analysis showed that the sensory attributes were associated with a group of VCs and not by a single compound119839849FUNDAÇÃO DE AMPARO À PESQUISA DO ESTADO DE SÃO PAULO - FAPESP2016/15012-2The authors are grateful to the São Paulo Research Foundation (FAPESP, Brazil) for funding the project No. 2016/15012-2. Erick Saldaña received the support of the “Consejo Nacional de Ciencia, Tecnología e Innovación Tecnológica - CONCYTEC” from Peru, in the framework of the CIENCIACTIVA programme, through the award of a PhD scholarship under contract agreement No. 104-2016-FONDECY