Explore the vast range of titles available.

Membrane bilayers are made up of a myriad of different lipids that regulate the functional activity, stability, and oligomerization of many membrane proteins. Despite their importance, screening the structural and functional impact of lipid–protein interactions to identify specific lipid requirements remains a major challenge. Here, we use the FSEC-TS assay to show cardiolipin-dependent stabilization of the dimeric sodium/proton antiporter NhaA, demonstrating its ability to detect specific protein-lipid interactions. Based on the principle of FSEC-TS, we then engineer a simple thermal-shift assay (GFP-TS), which facilitates the high-throughput screening of lipid- and ligand- interactions with membrane proteins. By comparing the thermostability of medically relevant eukaryotic membrane proteins and a selection of bacterial counterparts, we reveal that eukaryotic proteins appear to have evolved to be more dependent to the presence of specific lipids. Membrane bilayers are made up of a myriad of different lipids that affect membrane proteins, but identifying those specific lipid requirements remains a challenge. Here authors present an engineered thermal-shift screen which reveals specific lipid preferences of eukaryotic and prokaryotic membrane proteins.

Antibiotic resistance is a global health crisis that requires urgent action to stop its spread. To counteract the spread of antibiotic resistance, we must improve our understanding of the origin and spread of resistant bacteria in both community and healthcare settings. Unfortunately, little attention is being given to contain the spread of antibiotic resistance in community settings (i.e., locations outside of a hospital inpatient, acute care setting, or a hospital clinic setting), despite some studies have consistently reported a high prevalence of antibiotic resistance in the community settings. This study aimed to investigate the prevalence of antibiotic resistance in commensal Escherichia coli isolates from healthy humans in community settings in LMICs. Using the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines, we synthesized studies conducted from 1989 to May 2020. A total of 9363 articles were obtained from the search and prevalence data were extracted from 33 articles and pooled together. This gave a pooled prevalence of antibiotic resistance (top ten antibiotics commonly prescribed in LMICs) in commensal  E. coli  isolates from human sources in community settings in LMICs of: ampicillin (72% of 13,531 isolates, 95% CI: 65–79), cefotaxime (27% of 6700 isolates, 95% CI: 12–44), chloramphenicol (45% of 7012 isolates, 95% CI: 35–53), ciprofloxacin (17% of 10,618 isolates, 95% CI: 11–25), co-trimoxazole (63% of 10,561 isolates, 95% CI: 52–73), nalidixic acid (30% of 9819 isolates, 95% CI: 21–40), oxytetracycline (78% of 1451 isolates, 95% CI: 65–88), streptomycin (58% of 3831 isolates, 95% CI: 44–72), tetracycline (67% of 11,847 isolates, 95% CI: 59–74), and trimethoprim (67% of 3265 isolates, 95% CI: 59–75). Here, we provided an appraisal of the evidence of the high prevalence of antibiotic resistance by commensal  E. coli  in community settings in LMICs. Our findings will have important ramifications for public health policy design to contain the spread of antibiotic resistance in community settings. Indeed, commensal  E. coli is the main reservoir for spreading antibiotic resistance to other pathogenic enteric bacteria via mobile genetic elements.

Solute carrier (SLC) transporters represent the second-largest fraction of the membrane proteome after G-protein-coupled receptors, but have been underutilized as drug targets and the function of many members of this family is still unknown. They are technically challenging to work with as they are difficult to express and highly dynamic, making them unstable in detergent solution. Many SLCs lack known inhibitors that could be utilized for stabilization. Furthermore, as they bind their physiological substrates with high micromolar to low millimolar affinities, binding and transport assays have proven to be particularly challenging to implement. Previously, we reported a GFP-based method for the overexpression and purification of membrane proteins in Saccharomyces cerevisiae . Here, we extend this expression platform with the GFP thermal shift (GFP-TS) assay, which is a simplified version of fluorescence-detection size-exclusion chromatography that combines the sample versatility of fluorescence-detection size-exclusion chromatography with the high-throughput capability of dye-based thermal shift assays. We demonstrate how GFP-TS can be used for detecting specific ligand interactions of SLC transporter fusions and measuring their affinities in crude detergent-solubilized membranes. We further show how GFP-TS can be employed on purified SLC transporter fusions to screen for specific lipid–protein interactions, which is an important complement to native mass spectrometry approaches that cannot cope easily with crude lipid-mixture preparations. This protocol is simple to perform and can be followed by researchers with a basic background in protein chemistry. Starting with an SLC transporter construct that can be expressed and purified from S. cerevisiae in a well-folded state, this protocol extension can be completed in ~4–5 d. This protocol extension describes the GFP thermal shift assay for monitoring ligand interactions of solute carrier transporters using either crude detergent-solubilized membranes or purified samples.

The decoration of secretory glycoproteins and glycolipids with sialic acid is critical to many physiological and pathological processes. Sialyation is dependent on a continuous supply of sialic acid into Golgi organelles in the form of CMP-sialic acid. Translocation of CMP-sialic acid into Golgi is carried out by the CMP-sialic acid transporter (CST). Mutations in human CST are linked to glycosylation disorders, and CST is important for glycopathway engineering, as it is critical for sialyation efficiency of therapeutic glycoproteins. The mechanism of how CMP-sialic acid is recognized and translocated across Golgi membranes in exchange for CMP is poorly understood. Here we have determined the crystal structure of a Zea mays CST in complex with CMP. We conclude that the specificity of CST for CMP-sialic acid is established by the recognition of the nucleotide CMP to such an extent that they are mechanistically capable of both passive and coupled antiporter activity.Crystal structures of a Zea mays CMP-sialic acid transporter (CST) apo and in complex with CMP and functional assays of corn and human CSTs suggest how CMP-sialic acid is translocated across Golgi membranes.

Microsomal glutathione S-transferase 2 (MGST2) produces leukotriene C 4 , key for intracrine signaling of endoplasmic reticulum (ER) stress, oxidative DNA damage and cell death. MGST2 trimer restricts catalysis to only one out of three active sites at a time, but the molecular basis is unknown. Here, we present crystal structures of human MGST2 combined with biochemical and computational evidence for a concerted mechanism, involving local unfolding coupled to global conformational changes that regulate catalysis. Furthermore, synchronized changes in the biconical central pore modulate the hydrophobicity and control solvent influx to optimize reaction conditions at the active site. These unique mechanistic insights pertain to other, structurally related, drug targets. Microsomal glutathione S-transferase 2 (MGST2) produces leukotriene C 4 , an intracrine mediator of cell death. Structural, biochemical and computational analyses of human MGST2 suggest a mechanism employed by the enzyme to restrict catalysis to only one active site within the MGST2 trimer.

Without addressing the lack of research infrastructure, funding, and supportive science policies, structural biology capacity-building efforts in Africa will continue to be hindered by the persistent challenge of brain drain.

Under conditions of extreme acidity, the lysine-specific permease, LysP, not only mediates the import of L-lysine it also interacts with the transcriptional regulator, CadC, to activate expression of the cadAB operon. This operon encodes the lysine decarboxylase, CadA, which converts lysine to cadaverine while consuming a cytoplasmic proton, and the antiporter, CadB, which exports protonated cadaverine in exchange for extracellular lysine. Together, these processes contribute to cytoplasmic pH homeostasis and support bacterial acid resistance - a mechanism essential for the survival of pathogenic bacteria in acidic host environments. Here, we present the cryo-EM structure of LysP from Pseudomonas aeruginosa in an inward-occluded conformation (3.2–5.3 Å resolution), bound to L-lysine and a nanobody. L-Lysine is coordinated by hydrophobic contacts, cation–π interactions, and by hydrogen bonding mostly with polar uncharged residues. Reconstitution of LysP into proteoliposomes confirms specific L-lysine transport, which is competitively inhibited by L-4-thialysine. These findings provide a structural framework for understanding selective lysine recognition and inhibition, with implications for antibacterial drug design. Pseudomonas aeruginosa survives extreme acidity by importing lysine through the LysP transporter to regulate acid-resistance genes. Here, authors reveal the cryo-EM structure of LysP and show how specific hydrogen bonds enable lysine recognition.

Cervical cancer is a malignant proliferation of the cells of the uterine cervix and can be treated if diagnosed earlier. It is the second most common gynecological malignancy worldwide and the leading cause of cancer associated mortality among women in Africa and Cameroon. This study sort to determine the current state of knowledge of cervical cancer and its risk factors in the Buea Health District of the South West Region of Cameroon. This was a cross-sectional community based survey. We recruited 433 eligible women, in four (4) Health Areas (Molyko, Bolifamba, Muea and Buea Town) of the Buea Health District and used validated and pre-tested questionnaires to collect data. Collected data were keyed into Epi info version 7.2 statistical software and exported to SPSS Version 25 for analysis. Level of significance was set at P-value < 0.05. Fifty eight percent (58%) of the participants had good knowledge of cervical cancer. 58.99% (95%CI = 54.30-63.52) had good knowledge on the risk factors of cervical cancer. 40% knew at least one of the following risk factors; cigarette smoking, many sexual partners, family history of cervical cancer, being HIV/AIDS positive and giving birth 5 or more times. There was a significant association, OR = 7.5; 95%CI = 2.14-26.33; P = 0.001; X = 11.4 between having heard of cervical cancer and having \"good\" knowledge of cervical cancer among women in Buea. Most of the women had heard of cervical cancer but the knowledge of the risk factors of cervical cancer among women aged 18-68 years in the Buea Health District is low. We found no association between awareness and knowledge of risk factors among the women.

The African Light Source (AfLS) project is now almost eight years old. This article assesses the history, current context and future of the project. There is by now considerable momentum in building the user community, including deep training, facilitating access to current facilities, growing the scientific output, scientific networks and growing the local laboratory‐scale research infrastructure. The Conceptual Design Report for the AfLS is in its final editing stages. This document specifies the socio‐economic and scientific rationales and the technical aspects amongst others. The AfLS is supported by many national and Pan‐African scientific professional bodies and voluntary associates across many scientific disciplines, and there are stakeholders throughout the continent and beyond. The current roadmap phases have expanded to include national and Pan‐African level conversations with policy makers through new Strategic Task Force groups. The document summarizes this progress and discusses the future of the project. The African Light Source project towards a light source for the African continent is described.

The majority of existing studies aimed at investigating the incidence and prevalence of multidrug-resistance by bacteria have been performed in healthcare settings. Relatively few studies have been conducted in community settings, but these have consistently shown a high prevalence of multidrug-resistant bacteria in low- and middle-income countries (LMICs). To provide an appraisal of the evidence on the high prevalence of multidrug-, extensive drug-, and pandrug-resistance in commensal Escherichia coli isolates from human sources in community settings in LMICs. Using the preferred reporting items for systematic reviews and meta-analyses (PRISMA) guidelines, PubMed, EMBASE, MEDLINE, Web of Science, CINAHL, and Cochrane Library databases were systematically searched with the search string: 'Enterobacteriaceae', OR 'E. coli', OR 'Escherichia coli', AND 'antibiotic resistance', OR 'antimicrobial resistance', OR 'drug-resistance', AND 'prevalence', OR 'incidence', OR 'morbidity', OR 'odds ratio', OR 'risk ratio', OR 'confidence interval', OR 'p-value', OR 'rate'. Data were extracted and proportional meta-analysis was performed using the Freeman-Tukey transformation random effect model. The prevalence of multidrug-, extensive drug- and pandrug-resistance were extracted from articles that met our inclusion criteria and pooled together after a systematic screening of 9,369 items. The prevalence of multidrug-resistance was 28% of 14,336 total cases of isolates tested, 95% CI: 23-32. Extensive drug-resistance was 24% of 8,686 total cases of isolates tested, 95% CI: 14-36. Lastly, pandrug-resistance was 5% of 5,670 total cases of isolates tested, 95% CI: 3-8. This paper provides an appraisal of the evidence on the high prevalence of multidrug-, extensive drug- and pandrug-resistance by commensal E. coli in community settings in LMICs. Our results call for greater effort to be placed at the community level in the design of new and improved public health policies to counter the global threat of antibiotic-resistant infections and bacteria.