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991.
DiGuistini S Wang Y Liao NY Taylor G Tanguay P Feau N Henrissat B Chan SK Hesse-Orce U Alamouti SM Tsui CK Docking RT Levasseur A Haridas S Robertson G Birol I Holt RA Marra MA Hamelin RC Hirst M Jones SJ Bohlmann J Breuil C 《Proceedings of the National Academy of Sciences of the United States of America》2011,108(6):2504-2509
992.
Kachalova G Decker K Holt A Bartunik HD 《Proceedings of the National Academy of Sciences of the United States of America》2011,108(12):4800-4805
FAD-linked oxidases constitute a class of enzymes which catalyze dehydrogenation as a fundamental biochemical reaction, followed by reoxidation of reduced flavin. Here, we present high-resolution crystal structures showing the flavoenzyme 6-hydroxy-l-nicotine oxidase in action. This enzyme was trapped during catalytic degradation of the native substrate in a sequence of discrete reaction states corresponding to the substrate-reduced enzyme, a complex of the enzyme with the intermediate enamine product and formation of the final aminoketone product. The inactive d-stereoisomer binds in mirror symmetry with respect to the catalytic axis, revealing absolute stereospecificity of hydrogen transfer to the flavin. The structural data suggest deprotonation of the substrate when bound at the active site, an overall binary complex mechanism and oxidation by direct hydride transfer. The amine nitrogen has a critical role in the dehydrogenation step and may activate carbocation formation at the α-carbon via delocalization from the lone pair to σ* C(α)-H. Enzymatically assisted hydrolysis of the intermediate product occurs at a remote (P?site) cavity. Substrate entry and product exit follow different paths. Structural and kinetic data suggest that substrate can also bind to the reduced enzyme, associated with slower reoxidation as compared to the rate of reoxidation of free enzyme. The results are of general relevance for the mechanisms of flavin amine oxidases. 相似文献
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994.
ECM components guide IL-10 producing regulatory T-cell (TR1) induction from effector memory T-cell precursors 总被引:1,自引:0,他引:1
995.
Draft genome of the red harvester ant Pogonomyrmex barbatus 总被引:3,自引:0,他引:3
Smith CR Smith CD Robertson HM Helmkampf M Zimin A Yandell M Holt C Hu H Abouheif E Benton R Cash E Croset V Currie CR Elhaik E Elsik CG Favé MJ Fernandes V Gibson JD Graur D Gronenberg W Grubbs KJ Hagen DE Viniegra AS Johnson BR Johnson RM Khila A Kim JW Mathis KA Munoz-Torres MC Murphy MC Mustard JA Nakamura R Niehuis O Nigam S Overson RP Placek JE Rajakumar R Reese JT Suen G Tao S Torres CW Tsutsui ND Viljakainen L Wolschin F Gadau J 《Proceedings of the National Academy of Sciences of the United States of America》2011,108(14):5667-5672
We report the draft genome sequence of the red harvester ant, Pogonomyrmex barbatus. The genome was sequenced using 454 pyrosequencing, and the current assembly and annotation were completed in less than 1 y. Analyses of conserved gene groups (more than 1,200 manually annotated genes to date) suggest a high-quality assembly and annotation comparable to recently sequenced insect genomes using Sanger sequencing. The red harvester ant is a model for studying reproductive division of labor, phenotypic plasticity, and sociogenomics. Although the genome of P. barbatus is similar to other sequenced hymenopterans (Apis mellifera and Nasonia vitripennis) in GC content and compositional organization, and possesses a complete CpG methylation toolkit, its predicted genomic CpG content differs markedly from the other hymenopterans. Gene networks involved in generating key differences between the queen and worker castes (e.g., wings and ovaries) show signatures of increased methylation and suggest that ants and bees may have independently co-opted the same gene regulatory mechanisms for reproductive division of labor. Gene family expansions (e.g., 344 functional odorant receptors) and pseudogene accumulation in chemoreception and P450 genes compared with A. mellifera and N. vitripennis are consistent with major life-history changes during the adaptive radiation of Pogonomyrmex spp., perhaps in parallel with the development of the North American deserts. 相似文献
996.
997.
Martin Holt Joanne Bryant Christy E. Newman Dana M. Paquette Limin Mao Michael R. Kidd Deborah C. Saltman Susan C. Kippax 《International journal of mental health and addiction》2012,10(2):141-151
Our aim was to clarify the role of alcohol and other drug (AOD) use in major depression among gay men attending general medical
practices. A secondary analysis was conducted on survey data collected from 531 gay men attending high-HIV-caseload general
practices in Adelaide and Sydney, Australia. The survey contained demographic, social, behavioural and AOD variables. Participants
were classified into those with (n = 130) and without major depression (n = 401) using the PHQ-9 screening tool. Although rates of drug use were very high in the sample, multivariate logistic regression
analysis showed that the majority of variables independently associated with major depression were social and behavioural
factors. Only one AOD variable was associated with major depression: the use of three or more drug types in the past 6 months.
Attending to specific patterns of AOD use may assist in the identification of gay men most at risk of major depression. 相似文献
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