Latest Publications
Enset Bacterial Wilt (Xanthomonas vasicola pv. musacearum): Farmer Perspectives, Physicochemical Characterization, and Phenotypic Variation Among Strains
Tafesse Kibatu, Sebsebe Demissew, Diriba Muleta, Getahun Haile, Seman Abrar, Denberu Kebede, Murray Grant, Sadik Muzemil, Tileye Feyissa
Enset is a staple food for approximately 25% of Ethiopia’s population. It is threatened by a range of biotic and abiotic stress, of which bacterial wilt is the most significant. This study investigated the enset bacterial wilt (EBW) status on farms in Gedeo, Kembata Tembaro, Gurage, Hadiya zones, and the Basketo special woreda of Southern Ethiopia. In addition, infected enset plant samples were collected from Hadiya, Kembata Tembaro, and Gedeo zones to assess bacterial strain diversity using physicochemical and morphological approaches. Representative Kebeles were selected using purposive sampling based on their agroecological conditions. Data was collected through in-depth interviews, questionnaires, group discussions, and field observation. The morphology of bacterial wilt isolates was characterized by color, texture, form, elevation, margin, and motility. In addition, a combination of oxidase, aesculin hydrolysis, catalase, gram reaction, hydrogen sulfide (H2S), gelatin liquefaction, and fructose, lactose, mannitol, and sorbitol utilization tests were conducted to capture physiochemical differences. Tolerance to salt and high temperatures was also evaluated. The bacterial wilt impact varies significantly across enset growing regions, with highlands experiencing the highest. This research emphasizes the importance of assessing both spatial and temporal variation, as well as integrating local knowledge and robust scientific approaches for effective bacterial wilt management and enset landrace conservation efforts. The research also provides valuable insights into the characteristics of bacterial wilt isolates in Southern Ethiopia. Analyses of morphology, potassium hydroxide solubility, catalase activity, and carbohydrate utilization were consistent, however, variations in bacterial isolates response to tests of easculin, oxidase, gelatin liquid, H2S tests and response to osmotic and temperature exposures. This study reveals a strong association between the bacterial wilt effect and the enset growing regions. EBW exhibits seasonal fluctuations. Bacterial wilt isolates displayed consistent morphological characteristics. All isolates similarly utilized sorbitol, mannitol, lactose, and fructose carbohydrates. All isolates exhibited positive potassium hydroxide solubility and catalase activity. However, the isolates displayed variations in responses to easculin, oxidase, gelatin liquefaction, and H2S production. The isolates also displayed variations in tolerance to salt and high temperatures. These variations can be valuable for understanding disease epidemiology and management.
Between‐country differences in the psychosocial profiles of British cattle farmers
Naomi S. Prosser, Eamonn Ferguson, Jasmeet Kaler, Edward M. Hill, Michael J. Tildesley, Matt J. Keeling, Martin J. Green
BACKGROUND: Psychosocial factors are important for the uptake of livestock disease control measures by farmers and can differ by region, which would have implications for disease control nationally.
METHODS: We investigated altruism, trust, psychological proximity and the COM-B behaviour change framework in a survey of 475 British cattle farmers in 2020. Using regression models, we studied associations between the country farmers lived in and psychosocial and behaviour change factors. RESULTS: There were many between-country differences in farmers' psychosocial and COM-B profiles. Accounting for multiple tests, Scottish cattle farmers reported higher trust in governmental judgements for disease control and greater social opportunity to control disease than English cattle farmers.
LIMITATIONS: There were relatively low numbers of respondents from Scotland and Wales. As such, the results should be interpreted with caution. Northern Irish farmers could not be included in the analyses as there were too few responses.
CONCLUSION: Cattle farmers differed in their psychosocial profiles by country. Our sample of Scottish farmers reported higher trust in, and felt better supported by, government in the context of disease control than the English farmers, which could be due to different disease control approaches between devolved governments. Understanding between-country differences in farmer psychosocial attributes has implications for animal health governance and approaches to disease control.
Mechanisms of permselectivity of connexin hemichannels to small molecules
Connexins can act either as hemichannels to facilitate ion and small-molecule movement from the cytosol to the extracellular space or as gap junction channels to provide a pathway for solute exchange between cells. Connexins are ubiquitously expressed throughout the body and are implicated in a wide range of processes. The permselectivity of connexin hemichannels for small neurochemicals remains poorly understood. By coexpressing genetically encoded fluorescent sensors for ATP, glutamate, and lactate with a range of connexins, we examined the ability of different hemichannels to permit the release of these compounds under physiological conditions and in response to physiological stimuli (small changes in partial pressure of CO2 and transmembrane depolarization). We found that some connexin hemichannels were relatively nonselective (Cx26, Cx32, Cx43, and Cx31.1) allowing passage of ATP, glutamate, and lactate. By contrast, other connexin hemichannels (Cx36, Cx46, and Cx50) were highly selective. Cx36 and Cx46 hemichannels allowed the release of ATP but not glutamate or lactate. The size of the permeating molecule cannot be the sole determinant of permselectivity. By contrast, Cx50 hemichannels permitted the release of lactate and glutamate but not ATP. We also found that the nature of the opening stimulus could alter the permselectivity of the hemichannel—for some of the relatively nonselective connexins, hemichannel opening via depolarization was ineffective at allowing the release of lactate. By performing a mutational analysis, informed by the differential selectivity of the closely related Cx46 and Cx50 hemichannels, we found that the charge on the N terminus and N terminus–transmembrane 2 interactions are key contributors to permselectivity for ATP.
Discovery of Late Intermediates in Methylenomycin Biosynthesis Active against Drug-Resistant Gram-Positive Bacterial Pathogens
Christophe Corre, Gideon A. Idowu, Lijiang Song, Melanie E. Whitehead, Lona M. Alkhalaf, Gregory L. Challis
The methylenomycins are highly functionalized cyclopentanone antibiotics produced by Streptomyces coelicolor A3(2). A biosynthetic pathway to the methylenomycins has been proposed based on sequence analysis of the proteins encoded by the methylenomycin biosynthetic gene cluster and the incorporation of labeled precursors. However, the roles played by putative biosynthetic enzymes remain experimentally uninvestigated. Here, the biosynthetic functions of enzymes encoded by mmyD, mmyO, mmyF, and mmyE were investigated by creating in-frame deletions in each gene and investigating the effect on methylenomycin production. No methylenomycin-related metabolites were produced by the mmyD mutant, consistent with the proposed role of MmyD in an early biosynthetic step. The production of methylenomycin A, but not methylenomycin C, was abolished in the mmyF and mmyO mutants, consistent with the corresponding enzymes catalyzing the epoxidation of methylenomycin C, as previously proposed. Expression of mmyF and mmyO in a S. coelicolor M145 derivative engineered to express mmr, which confers methylenomycin resistance, enabled the resulting strain to convert methylenomycin C to methylenomycin A, confirming this hypothesis. A novel metabolite (premethylenomycin C), which readily cyclizes to form the corresponding butanolide (premethylenomycin C lactone), accumulated in the mmyE mutant, indicating the corresponding enzyme is involved in introducing the exomethylene group into methylenomycin C. Remarkably, both premethylenomycin C and its lactone precursor were one to two orders of magnitude more active against various Gram-positive bacteria, including antibiotic-resistant Staphylococcus aureus and Enterococcus faecium isolates, than methylenomycins A and C, providing a promising starting point for the development of novel antibiotics to combat antimicrobial resistance.
Protein Target Highlights in CASP16: Insights From the Structure Providers
Leila T. Alexander, Océane M. Follonier, Andriy Kryshtafovych,| Kim Abesamis, Sabrina Bibi-Triki, Henry G. Box, Cécile Breyton, Françoise Bringel, Loic Carrique, Alessio d'Acapito, Gang Dong, Rebecca DuBois, Deborah Fass, JulianaMartinez Fiesco, Daniel R. Fox, Jonathan M. Grimes, Rhys Grinter, Matthew Jenkins, Roman Kamyshinsky, Jeremy R. Keown, Gerald Lackner, Michael Lammers, Shiheng Liu, Andrew L. Lovering,Tomas Malinauskas, Benoît Masquida, Gottfried J. Palm, Christian Siebold,Tiantian Su, Ping Zhang, Z. Hong Zhou, Krzysztof Fidelis, Maya Topf, John Moult, Torsten Schwed
This article presents an in-depth analysis of selected CASP16 targets, with a focus on their biological and functional significance. The authors highlight the most relevant features of the target proteins and discuss how well these were reproduced in the submitted predictions. While the overall performance of structure prediction methods remains impressive, challenges persist, particularly in modeling rare structural motifs, flexible regions, small molecule interactions, posttranslational modifications, and biologically important interfaces. Addressing these limitations can strengthen the role of structure prediction in complementing experimental efforts and advancing both basic research and biomedical applications.
Proteins (Structure, Function, Bioinformatics), October 2025
StayRose: A photostable StayGold derivative redshifted by genetic code expansion
Will Scott, Esther Ivorra-Molla, Dipayan Akhuli, Teresa Massam-Wu, Pawel K. Lysyganicz, Rylie Walsh, Matthew Parent, Jonathan Cook, Lijiang Song, Abhishek Kumar, Falk Schneider, Masanori Mishima, Allister Crow, Mohan K. Balasubramanian
Photobleaching of fluorescent proteins often limits the acquisition of high-quality images in microscopy. StayGold, a novel dimeric GFP recently monomerized through sequence engineering, addresses this challenge with its high photostability. There is now a focus on producing different colored StayGold derivatives to facilitate concurrent tagging of multiple targets. The unnatural amino acid 3-aminotyrosine has previously been shown to redshift superfolder GFP upon incorporation into its chromophore via genetic code expansion. Here, we apply the same strategy to redshift StayGold through substitution of tyrosine-58 with 3-aminotyrosine. The resultant red fluorescent protein, StayRose, shows an excitation wavelength maximum of 530 nm and an emission wavelength maximum of 588 nm. Importantly, the monomeric mStayRose retains the favorable photostability in vivo in Escherichia coli and zebrafish embryos. A high-resolution crystal structure of StayRose confirms the modified structure of the amino chromophore within an unperturbed 3D fold. Although reliant on genetic code expansion, StayRose provides an important step toward developing redshifted StayGold derivatives.