排序方式: 共有8条查询结果,搜索用时 0 毫秒
1
1.
2.
Ratje AH Loerke J Mikolajka A Brünner M Hildebrand PW Starosta AL Dönhöfer A Connell SR Fucini P Mielke T Whitford PC Onuchic JN Yu Y Sanbonmatsu KY Hartmann RK Penczek PA Wilson DN Spahn CM 《Nature》2010,468(7324):713-716
The elongation cycle of protein synthesis involves the delivery of aminoacyl-transfer RNAs to the aminoacyl-tRNA-binding site (A?site) of the ribosome, followed by peptide-bond formation and translocation of the tRNAs through the ribosome to reopen the A?site. The translocation reaction is catalysed by elongation factor G (EF-G) in a GTP-dependent manner. Despite the availability of structures of various EF-G-ribosome complexes, the precise mechanism by which tRNAs move through the ribosome still remains unclear. Here we use multiparticle cryoelectron microscopy analysis to resolve two previously unseen subpopulations within Thermus thermophilus EF-G-ribosome complexes at subnanometre resolution, one of them with a partly translocated tRNA. Comparison of these substates reveals that translocation of tRNA on the 30S subunit parallels the swivelling of the 30S head and is coupled to unratcheting of the 30S body. Because the tRNA maintains contact with the peptidyl-tRNA-binding site (P?site) on the 30S head and simultaneously establishes interaction with the exit site (E?site) on the 30S platform, a novel intra-subunit 'pe/E' hybrid state is formed. This state is stabilized by domain?IV of EF-G, which interacts with the swivelled 30S-head conformation. These findings provide direct structural and mechanistic insight into the 'missing link' in terms of tRNA intermediates involved in the universally conserved translocation process. 相似文献
3.
Trachytes kaliszewskii, n. sp., is described from the Great Basin, Utah, USA. SEM photography illustrates morphological detail. An annotated list is included of currently recognized species of the genus Trachytes , with comments on their distribution and habitat characteristics. 相似文献
4.
COMPLEX ECO-ECONOMY SYSTEM 总被引:4,自引:0,他引:4
PawelBartoszczuk YoshiteruNakamori 《系统科学与复杂性》2003,16(2):145-158
In the past there were a lot of researches on the topic of economic growth. Nevertheless, the environment has been a bit abstracted by standard economics. Scarce natural resources and our choices to protect them or exploit them jointly determine the economic and environmental systems. In this paper we describe a model with a particular focus on the relationship among income, pollution, and non-renewable resources. We want to combine both economic and environmental sectors. The system dynamics approach is used in analyzing these complex relationships. This paper gives an insight into the possibilities for replacing non-renewable resources with more renewable ones. Next, we present the simulation runs of the model that are conducted with the help of existing system dynamics modeling tools. Only the relationships simulated so far between the variables ought to be put under yet more cautious examination. 相似文献
5.
Cichon S Buervenich S Kirov G Akula N Dimitrova A Green E Schumacher J Klopp N Becker T Ohlraun S Schulze TG Tullius M Gross MM Jones L Krastev S Nikolov I Hamshere M Jones I Czerski PM Leszczynska-Rodziewicz A Kapelski P Bogaert AV Illig T Hauser J Maier W Berrettini W Byerley W Coryell W Gershon ES Kelsoe JR McInnis MG Murphy DL Nurnberger JI Reich T Scheftner W O'Donovan MC Propping P Owen MJ Rietschel M Nöthen MM McMahon FJ Craddock N 《Nature genetics》2004,36(8):783-4; author reply 784-5
6.
Cornelius F Boerkoel Hiroshi Takashima Joy John Jiong Yan Pawel Stankiewicz Lisa Rosenbarker Jean-Luc André Radovan Bogdanovic Antoine Burguet Sandra Cockfield Isabel Cordeiro Stefan Fründ Friederike Illies Mark Joseph Ilkka Kaitila Giuliana Lama Chantal Loirat D Ross McLeod David V Milford Elizabeth M Petty Francisco Rodrigo Jorge M Saraiva Beate Schmidt Graham C Smith Jürgen Spranger Anja Stein Hannelore Thiele Jane Tizard Rosanna Weksberg James R Lupski David W Stockton 《Nature genetics》2002,30(2):215-220
Schimke immuno-osseous dysplasia (SIOD, MIM 242900) is an autosomal-recessive pleiotropic disorder with the diagnostic features of spondyloepiphyseal dysplasia, renal dysfunction and T-cell immunodeficiency. Using genome-wide linkage mapping and a positional candidate approach, we determined that mutations in SMARCAL1 (SWI/SNF2-related, matrix-associated, actin-dependent regulator of chromatin, subfamily a-like 1), are responsible for SIOD. Through analysis of data from persons with SIOD in 26 unrelated families, we observed that affected individuals from 13 of 23 families with severe disease had two alleles with nonsense, frameshift or splicing mutations, whereas affected individuals from 3 of 3 families with milder disease had a missense mutation on each allele. These observations indicate that some missense mutations allow retention of partial SMARCAL1 function and thus cause milder disease. 相似文献
7.
8.
1