Topological side-chain classification of beta-turns: Ideal motifs for peptidomimetic development

beta-turns are important topological motifs for biological recognition of proteins and peptides. Organic molecules that sample the side chain positions of beta-turns have shown broad binding capacity to multiple different receptors, for example benzodiazepines. beta-turns have traditionally been classified into various types based on the backbone dihedral angles (phi 2, psi 2, phi 3 and psi 3). Indeed, 57-68% of beta-turns are currently classified into 8 different backbone families (Type I, Type II, Type I', Type II', Type VIII, Type VIa1, Type VIa2 and Type VIb and Type IV which represents unclassified beta-turns). Although this classification of beta-turns has been useful, the resulting beta-turn types are not ideal for the design of beta-turn mimetics as they do not reflect topological features of the recognition elements, the side chains. To overcome this, we have extracted beta-turns from a data set of non-homologous and high-resolution protein crystal structures. The side chain positions, as defined by C-alpha-C-beta vectors, of these turns have been clustered using the kth nearest neighbor clustering and filtered nearest centroid sorting algorithms. Nine clusters were obtained that cluster 90% of the data, and the average intra-cluster RMSD of the four C-alpha-C-beta vectors is 0.36. The nine clusters therefore represent the topology of the side chain scaffold architecture of the vast majority of beta-turns. The mean structures of the nine clusters are useful for the development of beta-turn mimetics and as biological descriptors for focusing combinatorial chemistry towards biologically relevant topological space.

Do Australian public sector employees have the type of culture they want in the era of new public management?

New public management theory proposes that public sector organisations should be managed more like private sector organisations. It is therefore expected that public sector managers will have preferences for an organisational culture that will reflect the culture of private sector organisations, with an external rather than internal orientation. The current research investigated the idea that managers' perceptions of ideal organisational culture would be different to the bureaucratic model of culture (internally oriented), which has traditionally been associated with public sector organisations. Responses to a competing values culture inventory were received from 925 public sector employees. Results indicated that the bureaucratic model is still pervasive; however, managers prefer a culture that is more external, and less control focussed, as expected. Lower level employees expressed a desire for a culture that emphasised human relations values.