Structural and Functional Insights into the Pilotin-Secretin Complex of the Type II Secretion System

Gram-negative bacteria secrete virulence factors and assemble fibre structures on their cell surface using specialized secretion systems. Three of these, T2SS, T3SS and T4PS, are characterized by large outer membrane channels formed by proteins called secretins. Usually, a cognate lipoprotein pilot is essential for the assembly of the secretin in the outer membrane. The structures of the pilotins of the T3SS and T4PS have been described. However in the T2SS, the molecular mechanism of this process is poorly understood and its structural basis is unknown. Here we report the crystal structure of the pilotin of the T2SS that comprises an arrangement of four α-helices profoundly different from previously solved pilotins from the T3SS and T4P and known four α-helix bundles. The architecture can be described as the insertion of one α-helical hairpin into a second open α-helical hairpin with bent final helix. NMR, CD and fluorescence spectroscopy show that the pilotin binds tightly to 18 residues close to the C-terminus of the secretin. These residues, unstructured before binding to the pilotin, become helical on binding. Data collected from crystals of the complex suggests how the secretin peptide binds to the pilotin and further experiments confirm the importance of these C-terminal residues in vivo

Teaching: Natural or Cultural?

In this chapter I argue that teaching, as we now understand the term, is historically and cross-culturally very rare. It appears to be unnecessary to transmit culture or to socialize children. Children are, on the other hand, primed by evolution to be avid observers, imitators, players and helpers—roles that reveal the profoundly autonomous and self-directed nature of culture acquisition (Lancy in press a). And yet, teaching is ubiquitous throughout the modern world—at least among the middle to upper class segment of the population. This ubiquity has led numerous scholars to argue for the universality and uniqueness of teaching as a characteristically human behavior. The theme of this chapter is that this proposition is unsustainable. Teaching is largely a result of recent cultural changes and the emergence of modern economies, not evolution

“Double culturedness”: the “capital” of Inuit nurses

Background. The health and educational systems in Greenland and Nunavut are reflections of those in Denmark and Southern Canada, with the language of instruction and practise being Danish and English. This places specific demands on Inuit studying nursing. Objective. This paper discusses the experiences of Inuit who are educated in nursing programmes and practise in healthcare systems located in the Arctic but dominated by EuroCanadian and Danish culture and language. Design. Research was qualitative and ethnographic. It was conducted through 12 months of fieldwork in 5 Greenlandic and 2 Nunavut communities. Methods. Observation, participant observation, interviews, questionnaires and document review were used. The analytical framework involved Bourdieu’s concepts of capital and habitus. Results. Participants experienced degrees of success and well-being in the educational systems that are afforded to few other Canadian and Greenlandic Inuit. This success appeared to be based on nurses and students possessing, or having acquired, what I call “double culturedness”; this makes them able to communicate in at least 2 languages and cultures, including the ability to understand, negotiate and interact, using at least 2 ways of being in the world and 2 ways of learning and teaching. Conclusion. There continues to be a critical need for Inuit nurses with their special knowledge and abilities in the healthcare systems of the Arctic. Inuit nurses’ experiences will help inform the education and healthcare systems and point to areas in need of support and change in order to increase recruitment and retention of nursing students and practitioners

Family of origin coaching for clinicians in a child and adolescent mental health service

The role of the therapist as a person rather than only as a technician has become increasingly important in family therapy since the post-modern turn. Despite this there is a paucity of research exploring supervision models that focus on self-reflection, as opposed to clinical competence. This study documents the experience of a Family of Origin Coaching group, conducted with six clinicians and one supervisor working in a child and adolescent mental health service. A participatory action framework was used, with data analysed using grounded theory. A variety of benefits were reported, including personal development, an enhanced empathy towards clients and an ability to better cope with stressful team dynamics. Family of Origin coaching has the potential to yield benefits for clinicians as a compliment to traditional supervision. Issues of confidentiality and safety need to be addressed carefully, especially during times of organisational change or stress