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排序方式: 共有171条查询结果,搜索用时 31 毫秒
81.
82.
Koepp DM Schaefer LK Ye X Keyomarsi K Chu C Harper JW Elledge SJ 《Science (New York, N.Y.)》2001,294(5540):173-177
Cyclin E binds and activates the cyclin-dependent kinase Cdk2 and catalyzes the transition from the G1 phase to the S phase of the cell cycle. The amount of cyclin E protein present in the cell is tightly controlled by ubiquitin-mediated proteolysis. Here we identify the ubiquitin ligase responsible for cyclin E ubiquitination as SCFFbw7 and demonstrate that it is functionally conserved in yeast, flies, and mammals. Fbw7 associates specifically with phosphorylated cyclin E, and SCFFbw7 catalyzes cyclin E ubiquitination in vitro. Depletion of Fbw7 leads to accumulation and stabilization of cyclin E in vivo in human and Drosophila melanogaster cells. Multiple F-box proteins contribute to cyclin E stability in yeast, suggesting an overlap in SCF E3 ligase specificity that allows combinatorial control of cyclin E degradation. 相似文献
83.
Schaefer HF 《Science (New York, N.Y.)》1986,232(4756):1319
84.
Air quality of American homes 总被引:1,自引:0,他引:1
In a survey of particulate fallout in homes it was found that there is a relation between pollution inside and outside a home. The level inside the home also depends on the location of the home (urban, suburban, or rural). Bathrooms and kitchens show heavier particle fallout than living rooms or bedrooms. 相似文献
85.
Schaefer BF 《Science (New York, N.Y.)》2005,308(5726):1267-1268
86.
S H Boyer A N Noyes G R Vrablik L J Donaldson E W Schaefer C W Gray T F Thurmon 《Science (New York, N.Y.)》1971,171(967):182-185
Small quantities of unusual hemoglobins were found in 1 of 37 chimpanzees and 2 of 6 gorillas. In each genus these hemoglobins contain unique alpha chains that differ from the ordinary by eight to nine scattered amino acid changes. The unusual chains arise from a hitherto undetected hemoglobin (3)alpha locus. No (3)alpha products are found in most apes; accordingly, (3)alpha is considered synthetically inactive in all but a few reversion mutants. Indirect evidence that the inactive (3)alpha locus is juxtaposed to an active alpha locus together with the supposition that (3)alpha exists in man provides a setting wherein thalassemia might be produced by nonhomologous recombination between two loci. 相似文献
87.
88.
Bis(3-fluorosalicylaldehyde) ethylenediimine cobalt(II), a reversible oxygen-carrying compound, has been crystallized as a tetramer with two oxygen molecules bound to the four cobalt atomns, each oxygen molecule bridging between two metal atoms. These dimers are further linked by two bonds between the oxygen atom of the salicylaldehyde and the cobalt atom. The oxygen-to-oxygen distance, 1.21 angstroms in molecular oxygen, has increased to 1.308(28) angstroms (where the number in parentheses is the estimated standard deviation) in this compound, the shortest distance yet observed in sutch a bridging arrangement. 相似文献
89.
Schaefer VJ 《Science (New York, N.Y.)》1970,170(3960):851-852
When relatively clean country air is exposed to the saturated vapor of iodine or turpentine, very large numbers of condensation nuclei develop. It is believed that such air contains clusters of molecules that are polymerized by the vapor of turpentine or iodine to form nuclei. 相似文献
90.