ABSTRACT
Bacteria produce a variety of polysaccharides with functional roles in cell surface coating, surface and host interactions, and biofilms. We have identified an 'Orphan' bacterial cellulose synthase catalytic subunit (BcsA)-like protein found in four model pseudomonads, P. aeruginosa PA01, P. fluorescens SBW25, P. putida KT2440 and P. syringae pv. tomato DC3000. Pairwise alignments indicated that the Orphan and BcsA proteins shared less than 41% sequence identity suggesting they may not have the same structural folds or function. We identified 112 Orphans among soil and plant-associated pseudomonads as well as in phytopathogenic and human opportunistic pathogenic strains. The wide distribution of these highly conserved proteins suggest they form a novel family of synthases producing a different polysaccharide. In silico analysis, including sequence comparisons, secondary structure and topology predictions, and protein structural modelling, revealed a two-domain transmembrane ovoid-like structure for the Orphan protein with a periplasmic glycosyl hydrolase family GH17 domain linked via a transmembrane region to a cytoplasmic glycosyltransferase family GT2 domain. We suggest the GT2 domain synthesises ß-(1,3)-glucan that is transferred to the GH17 domain where it is cleaved and cyclised to produce cyclic-ß-(1,3)-glucan (CßG). Our structural models are consistent with enzymatic characterisation and recent molecular simulations of the PaPA01 and PpKT2440 GH17 domains. It also provides a functional explanation linking PaPAK and PaPA14 Orphan (also known as NdvB) transposon mutants with CßG production and biofilm-associated antibiotic resistance. Importantly, cyclic glucans are also involved in osmoregulation, plant infection and induced systemic suppression, and our findings suggest this novel family of CßG synthases may provide similar range of adaptive responses for pseudomonads.
Subject(s)
Polysaccharides , beta-Glucans , Humans , Polysaccharides/metabolism , Glucans , Protein Structure, Secondary , Biofilms , Pseudomonas aeruginosa/metabolism , Bacterial Proteins/metabolism , beta-Glucans/metabolismABSTRACT
The 7th Young Scientist Symposium, a meeting again organized as a hybrid online event by young scientists for young scientists under the umbrella of the European Bioanalysis Forum and in collaboration with the Universities of Bologna and Ghent, included a variety of interesting presentations on cutting-edge bioanalytical science and processes. On the morning of day 2, the meeting hosted their traditional Science Café around the theme: 'How has COVID-19 changed our future?' in which the Young Scientist Symposium organizing committee engaged with the delegates on how the COVID-19 pandemic has impacted the careers of young scientists working in a bioanalytical (industry or academic) laboratory, that is, things they lost, for good or for bad - things they gained, wanted or unwanted, things they learned about themselves and their industry. This manuscript provides feedback from those discussions.
Subject(s)
Chemistry Techniques, Analytical , COVID-19/epidemiology , COVID-19/virology , Europe , Humans , SARS-CoV-2/isolation & purificationABSTRACT
INTRODUCTION: Geographic access to emergency treatment remains an important public policy concern as rural emergency medical systems respond to various pressures to centralize services. Geographical Information Systems (GIS) are effective tools to determine what proportion of a given population is adequately served by existing or proposed service distributions. METHODS: This study compares 2 GIS approaches to determining whether recent standards of emergency care access established by the British Columbia Ministry of Health Services are being met in Northern British Columbia. In particular, we compare results obtained using the more commonly used straight-line, or "as the crow flies," method with those obtained using a more sophisticated method that estimates travel time using digitally referenced road network data. RESULTS: Both methods reveal that provincial standards of emergency access are not being met in Northern British Columbia. CONCLUSION: In terms of comparing the 2 approaches, the network technique indicated a lower level of access and was more accurate in identifying populations residing inside and outside the "golden hour" of emergency care.