| Autor: |
Yang, Q, Ménétret, J-F, Akey, IV, Plath, K, Rapoport, T A, Akey, C W |
| Zdroj: |
Microscopy and Microanalysis; July 1998, Vol. 4 Issue: 1, Number 1 Supplement 2 p960-961, 2p |
| Abstrakt: |
Protein translocation plays a critical role in the targeting of both soluble and membrane proteins to their correct intra- and inter-cellular compartments. We are studying the 3D architecture of two rather different translocation machines, the Nuclear Pore Complex (NPC) and the ribosome-Sec61p complex (translocon), with the aim of understanding their physical mechanisms of gating and transport. Towards this end, we are using single particle electron cryomicroscopy and 3D reconstruction of frozen hydrated specimens to obtain interpretable maps that are biologically relevant.Previous work suggested that a central channel complex (termed the transporter) is present in vertebrate NPCs. Based on classification studies of the transporter and STEM images of Chironomus NPCs caught translocating large mRNPs, we have hypothesized that the transport mechanism utilizes a double iris-like gating mechanism, in which oppositely facing gates located at either end of the transporter open asynchronously. Recently, we have extended our studies to yeast NPCs and shown that this organelle is markedly smaller than its vertebrate cousin. |
| Databáze: |
Supplemental Index |
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