Figure 17-53. Structure of a clathrin-coated vesicle.

Figure 17-53Structure of a clathrin-coated vesicle

(a) A typical clathrin-coated vesicle comprises a membrane-bounded vesicle (tan) about 40 nm in diameter surrounded by a fibrous network of 12 pentagons and 8 hexagons. The fibrous coat is constructed of 36 clathrin triskelions, one of which is shown here in red. One clathrin triskelion is centered on each of the 36 vertices of the coat. Coated vesicles having other sizes and shapes are believed to be constructed similarly: each vesicle contains 12 pentagons but a variable number of hexagons. (b) Detail of a clathrin triskelion. Each of the three clathrin heavy chains has aspecific bent structure. A clathrin light chain is attached to each heavy chain near the center; a globular domain is at each distal (outer) tip. Although it is not obvious in (a) or (b), each triskelion has an intrinsic curvature; when triskelions polymerize, they form a curved (not flat) structure. (c) An intermediate in the assembly of a clathrin coat, containing 10 of the final 36 triskelions, illustrates the intrinsic curvature and the packing of the clathrin triskelions. [Part (a) see B. M. F. Pearse, 1987, EMBO J. 6:2507; part (b) see B. Pishvaee and G. Payne, 1998, Cell 95:443.]

From: Section 17.10, Molecular Mechanisms of Vesicular Traffic

Cover of Molecular Cell Biology
Molecular Cell Biology. 4th edition.
Lodish H, Berk A, Zipursky SL, et al.
New York: W. H. Freeman; 2000.
Copyright © 2000, W. H. Freeman and Company.

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