Three-dimensional reconstruction of mammalian 40 S ribosomal subunit embedded in ice.
A platform-like structure, which appears equivalent to the platform or lobe structure of the 30 S subunit of the eubacterial ribosome, is observed in the reconstruction of the small 40 S ribosomal subunit from images of ice-embedded particles. This cup-shaped structure, 15.0 nm in side length and 13.5 nm wide at its rim, extends obliquely upward on the back of the subunit. Other previously characterized features of the 40 S subunit can readily be identified: the head with its prominent beak structure, the body with its two back lobes expressed as relatively small-scale features, and the two widely separated feet that comprise the base of the subunit.
Wadsworth Center for Laboratories and Research, New York State Department of Health, Albany 12201-0509.
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S
Srivastava
A
A
Verschoor
M
M
Radermacher
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R
Grassucci
J
J
Frank
D000818:Animals; D007053:Ice; D008322:Mammals; D008854:Microscopy, Electron / Q000379:methods; D011487:Protein Conformation; D012269:Ribosomal Proteins / Q000737:chemistry* / Q000648:ultrastructure
D007053:Ice; D012269:Ribosomal Proteins; C086117:Rpsa protein, rat