Conscription of proteins for new functionality. Technical progress report

This report focuses on research in the following areas: development of function-based screening routines; generating methods for sorting output of database searches; developing strategies for determining chemically relevant three-dimensional scaffolds; and the integration of computational methodologies into user friendly tools

Hinge-Like Motions in RNA Kink-Turns: The Role of the Second A-Minor Motif and Nominally Unpaired Bases

Kink-turn (K-turn) motifs are asymmetric internal loops found at conserved positions in diverse RNAs, with sharp bends in phosphodiester backbones producing V-shaped structures. Explicit-solvent molecular dynamics simulations were carried out for three K-turns from 23S rRNA, i.e., Kt-38 located at the base of the A-site finger, Kt-42 located at the base of the L7/L12 stalk, and Kt-58 located in domain III, and for the K-turn of human U4 snRNA. The simulations reveal hinge-like K-turn motions on the nanosecond timescale. The first conserved A-minor interaction between the K-turn stems is entirely stable in all simulations. The angle between the helical arms of Kt-38 and Kt-42 is regulated by local variations of the second A-minor (type I) interaction between the stems. Its variability ranges from closed geometries to open ones stabilized by insertion of long-residency waters between adenine and cytosine. The simulated A-minor geometries fully agree with x-ray data. Kt-58 and Kt-U4 exhibit similar elbow-like motions caused by conformational change of the adenosine from the nominally unpaired region. Despite the observed substantial dynamics of K-turns, key tertiary interactions are stable and no sign of unfolding is seen. We suggest that some K-turns are flexible elements mediating large-scale ribosomal motions during the protein synthesis cycle

Multiple constituencies of trust: a study of the Oman military

This paper presents findings from a study of employees' multiple trust foci. Social exchange theory and the notions of conceptual and cognitive distance are used to generate hypotheses on the anticipated effects of specific trust relationships on employees' attitudinal and behavioural outcomes such as intention to quit, job satisfaction, organizational commitment and organizational citizenship behaviours. Data from Omani military personnel suggest that employees distinguish between trust in the organization, trust in their direct boss and trust in co-workers. Several important attitudinal and behavioural outcomes are predicted by these specific trust foci