Lasalocid is a highly atypical polyether ionophoric antibiotic, firstly because it contains a type of aromatic ring normally associated with fungal polyketides, and secondly because the formation of its tetrahydropyran ring appears to contravene Baldwin's rules, which predict the kinetically preferred routes for cyclisation reactions in organic chemistry. The lasalocid biosynthetic gene cluster has been cloned from Streptomyces lasaliensis, and the las locus (73,533 bp) was found to contain seven modular polyketide synthase (PKS) genes, including all the activities necessary for the synthesis of the aromatic moiety. Specific deletion from the gene cluster of the flanking lasC gene, which is predicted to encode a flavin-linked epoxidase, abolished production both of lasalocid and of the minor cometabolite iso-lasalocid without leading to accumulation of an identifiable intermediate; this suggests that oxidative cyclisation to form the polyether rings takes place on the PKS before release of the full-length polyketide product. Meanwhile, a mutant in which the adjacent epoxide hydrolase lasB had been deleted produced iso-lasalocid only. Iso-lasalocid differs from lasalocid in the replacement of the tetrahydropyran ring by a tetrohydrofuran ring and represents the kinetically favoured product of cyclisation. The LasB epoxide hydrolase is therefore directly implicated in control of the stereochemical course of polyether ring formation during lasalocid biosynthesis.

Caught in the act: Intermediates in the biosynthesis of lasalocid A are captured in vivo by malonyl carba(dethia)‐N‐acetyl cysteamine probes. These species constitute novel snapshots of the timing of ether and aromatic ring formation, thus providing valuable insights for the reconstruction and the engineering of polyether biosynthetic pathways.

A library of functionalized chemical probes capable of reacting with ketosynthase-bound biosynthetic intermediates was prepared and utilized to explore in vivo polyketide diversification. Fermentation of ACP mutants of S. lasaliensis in the presence of the probes generated a range of unnatural polyketide derivatives, including novel putative lasalocid A derivatives characterized by variable aryl ketone moieties and linear polyketide chains (bearing alkyne/azide handles and fluorine) flanking the polyether scaffold. By providing direct information on microorganism tolerance and enzyme processing of unnatural malonyl-ACP analogues, as well as on the amenability of unnatural polyketides to further structural modifications, the chemical probes constitute invaluable tools for the development of novel mutasynthesis and synthetic biology.

The research explores the views of teachers about how their teaching is evaluated by others. The tensions between evaluations motivated by the drive to improve practice (school self-evaluation) and evaluation related to external accountability (external evaluation – inspection) are considered, linked to findings and ideas reported in the literature. The study was undertaken using interviews (which included reflection on critical incidents during inspection) and incorporated the use of drawings as a research tool. Much of the data gathering and analysis were undertaken by five Third-Year undergraduate Education Studies students working under the direction and tutorage of the author (Hopkins). The findings validated those reported in the literature about the negative experiences of external evaluation (inspection) and point towards ways in which these might be reduced. The use of drawings alongside semistructured interviews proved to be a particularly powerful means of eliciting teachers’ thinking and feeling. The involvement of undergraduates as co-researchers provided them with a rich and authentic opportunity to gain insights into the professional world of teachers which they were preparing to join.

Communication with teenage and young adult or adolescent and young adult (AYA) patients with cancer is critically important and not consistently taught in health care education. We have developed a local training for medical students to experience and join AYA cancer consultations to improve clinicians' abilities in the future. We have undertaken a systematic review of the literature, to provide a comprehensive overview of studies evaluating communication in this specific patient group, to guide clinical practice and future research. We searched MEDLINE, EMBASE, PsycINFO, Web of Science, and CINAHL databases for literature containing data relating to communication in AYAs previously treated for malignant disease. To ensure as comprehensive a review as possible, the researchers defined the AYA age range using the extremes used globally: 13-39 years. Two thousand eight hundred and thirty-seven articles were identified, which were reduced to 1517 after duplicates were removed. After handsearching references and citation tracking, 1556 abstracts were screened of which 40 full-text articles were assessed for eligibility. Only 12 met all inclusion criteria and were included in the final analysis. Young people want to be heard and have trust in their health care professionals (HCPs). They want to be involved in decisions about their care, and HCPs must establish who else the AYA wants to be involved in the decision-making process. AYAs want information to be given in an amount they can control and at a time preferred by them. Further education of communication skills, especially triadic communication, is essential for professionals involved in AYA care.