RIBOSOME (70S) at 25Å
Subject:
- Ribosome (70S)/ice embedded
View:
- Shaded surface representations in six(6) views related by rotation
around vertical axis.
The views correspond to those in Fig. 4
of Frank et al. (1995b).
SPIDER/WEB users: Threshold = 5.168016
Specimen source:
- Escherichia coli.
Specimen preparation:
- embedment in vitreous ice.
Electron microscopy:
- Micrographs of untilted specimen grids.
EM = Zeis Em912 using zero-loss energy filtering (14eV),
Defocus settings 2.0 and 2.5 microns.
Magnification:
- 52,000X. Pixel size = .38 nm.
Image processing:
- Orientation of 4300 Ribosome projections identified by
3D projection matching using low resolution
reference. (Penczek et al., 1994).
Reconstruction (SIRT) simultaneously performed
CTF correction (Zhu et al. submitted).
References:
- Frank, J., Zhu, J., Penczek, P., Li, Y.,
Srivastava, S., Verschoor, A., Radermacher, M.,
Grassucci, R., Lato, R.K., and Agrawal, R.K. (1995a),
Nature 376 : 441-444.
Frank, J., Verschoor, A., Li, Y., Zhu, J., Lato, R.K.,
Radermacher, M., Penczek, P., Grassucci, R.,
and Agrawal, R.K. (1995b), Biochem. Cell Biol.
73 : 757-765.
Penczek, P., Grassucci, R., and Frank, J. (1994)
Ultramicroscopy 53 : 251-270.
Model of translation: This is an interpretation of the
70s reconstruction in terms of
-
(i) the pathways of nRNA (orange),
-
(ii) nascent polypeptide chain (gold and olive: possible branches of 50s
tunnel), and
-
(iii) A- and P- side tRNAs (pink and green, respectively) (corresponds to
Fig. 6 in Frank et al. (1995b)).