Nicotinamide Adenine Dinucleotides Arrest Photoreduction of Class II DNA

All light sensitive members of the photolyase cryptochrome family rely on FAD as catalytic cofactor. Its activity is regulated by photoreduction, a light triggered electron transfer process from a conserved tryptophan triad to the flavin. The stability of the reduced flavin depends on available external electron donors and oxygen. In this study, we show for the class II photolyase of Methanosarcina mazei, MmCPDII, that it utilizes physiologically relevant redox cofactors NADH and NADPH for the formation of the semiquinoid FAD in a light dependent reaction. Using redox inert variants MmCPDII W388F and MmCPDII W360F, we demonstrate that photoreduction by NADH and NADPH requires the class II specific tryptophan cascade of MmCPDII. Finally, we confirmed that mutations in the tryptophan cascade can be introduced without any substantial structural disturbances by analyzing crystal structures of MmCPDII W388F, MmCPDII W360F and MmCPDII Y345

Beneficiation of red iron ore fines from Pyne Mine, Bessemer, Ala. /

Includes bibliographic references.Mode of access: Internet

Field-measured drag area is a key correlate of level cycling time trial performance

Drag area (Ad) is a primary factor determining aerodynamic resistance during level cycling and is therefore a key determinant of level time trial performance. However, Ad has traditionally been difficult to measure. Our purpose was to determine the value of adding field-measured Ad as a correlate of level cycling time trial performance. In the field, 19 male cyclists performed a level (22.1 km) time trial. Separately, field-determined Ad and rolling resistance were calculated for subjects along with projected frontal area assessed directly (AP) and indirectly (Est AP). Also, a graded exercise test was performed to determine $\dot {V}{O}_{2}$V̇O2 peak, lactate threshold (LT), and economy. $\dot {V}{O}_{2}$V̇O2 peak ($\mathrm{l}~\min ^{-1}$lmin−1) and power at LT were significantly correlated to power measured during the time trial (r = 0.83 and 0.69, respectively) but were not significantly correlated to performance time (r = − 0.42 and −0.45). The correlation with performance time improved significantly (p < 0.05) when these variables were normalized to Ad. Of note, Ad alone was better correlated to performance time (r = 0.85, p < 0.001) than any combination of non-normalized physiological measure. The best correlate with performance time was field-measured power output during the time trial normalized to Ad (r = − 0.92). AP only accounted for 54% of the variability in Ad. Accordingly, the correlation to performance time was significantly lower using power normalized to AP (r = − 0.75) or Est AP (r = − 0.71). In conclusion, unless normalized to Ad, level time trial performance in the field was not highly correlated to common laboratory measures. Furthermore, our field-measured Ad is easy to determine and was the single best predictor of level time trial performance

Structure of the bifunctional cryptochrome aCRY from Chlamydomonas reinhardtii

Photolyases and cryptochromes form an almost ubiquitous family of blue light photoreceptors involved in the repair and maintenance of DNA integrity or regulatory control. We found that one cryptochrome from the green alga Chlamydomonas reinhardtii CraCRY is capable of both, control of transcript levels and the sexual cycle of the alga in a positive germination and negative manner mating ability , as well as catalyzing the repair of UV DNA lesions. Its 1.6 crystal structure shows besides the FAD chromophore an aromatic tetrad that is indispensable in animal like type I cryptochromes for light driven change of their signaling active redox state and formation of a stable radical pair. Given CraCRY s catalytic activity as 6 4 photolyase in vivo and in vitro, we present the first co crystal structure of a cryptochrome with duplex DNA comprising a 6 4 pyrimidine pyrimidone lesion. This 2.9 structure reveals a distinct conformation for the catalytic histidine His1, H357, that challenges previous models of a single photon driven 6 4 photolyase mechanis

Flash reduction of iron ore /

Based on work done in cooperation with the University of Alabama.Includes bibliographical references.Mode of access: Internet

Fabrication and cost evaluation of experimental building brick from waste glass /

Based on work done under a cooperative agreement between the Bureau of Mines and the University of Alabama.Bibliography: p. 16-17.Mode of access: Internet

Dewatering Florida phosphate pebble rock slime by freezing techniques /

"June 1971"--Cover.Based on work done in cooperation with the University of Alabama.Includes bibliographical references.Mode of access: Internet

Sintering of pyrrhotite calcine /

Work done in cooperation with the University of Alabama and the United States Pipe and Foundry Company.Bibliographical references included.Mode of access: Internet