Origin of the Transient Electron Paramagnetic Resonance Signals in DNA Photolyase

DNA photolyase repairs pyrimidine dimer lesions in DNA through light- induced electron donation to the dimer. During isolation of the enzyme, the flavin cofactor necessary for catalytic activity becomes one-electron- oxidized to a semiquinone radical. In the absence of external reducing agents, the flavin can be cycled through the semiquinone radical to the fully reduced state with light-induced electron transfer from a nearby tryptophan residue. This cycle provides a convenient means of studying the process of electron transfer within the protein by using transient EPR. By studying the excitation wavelength dependence of the time-resolved EPR signals we observe, we show that the spin-polarized EPR signal reported earlier from this laboratory as being initiated by semiquinone photochemistry actually originates from the fully oxidized form of the flavin cofactor. Exciting the semiquinone form of the flavin produces two transient EPR signals: a fast signal that is limited by the time response of the instrument and a slower signal with a lifetime of approximately 6 ms. The fast component appears to correlate with a dismutation reaction occurring with the flavin. The longer lifetime process occurs on a time scale that agrees with transient absorption data published earlier; the magnetic field dependence of the amplitude of this kinetic component is consistent with redox chemistry that involves electron transfer between flavin and tryptophan. We also report a new procedure for the rapid isolation of DNA photolyase

Multiple team membership arrangements: putting the worker front and center

There are indicators we are entering a new era for MTM research, by moving beyond the structural approach that has characterized MTM research to date, to focus on important and under-researched issues, such as the nature of employees’ experiences in an MTM context. Although team research suggests that the experiences of members impact team functioning, these lines of reasoning have not, until recently, made their way to MTM research. To overcome this limitation, this symposium showcases five papers that use a variety of theoretical perspectives, research designs (i.e., qualitative, quantitative), contexts (e.g., healthcare, automotive manufacturer, online panels), methodologies, and analytical methods (i.e., meta-analysis, content/thematic analysis). The symposium focuses on surfacing and advancing unanswered questions that extend theory and can offer fruitful directions for MTM research by examining critical individual and team level outcomes (e.g., individual/team performance, individual counterproductive and organizational citizenship behavior, individual learning, individual turnover intentions, organizational commitment) in the experiences of MTM employees across their teams (e.g., goals, functions, roles). We hope to provide a forum to advance unanswered questions that offer fruitful directions for MTM research