Figure 21-1

Click on structure and drag to rotate. Click on figure to reset.

X-ray structure of human ubiquitin. The polypeptide is drawn in ribbon form colored in rainbow order from its N-terminus (blue) to its C-terminus (red) with the side chain of Lys 48 shown in stick form with C green and N blue. This α + β architecture is known as a β-Grasp fold because its β sheets appear to grasp its α helix. To best see this, orient the helix end-on. [Based on an X-ray structure by Charles Bugg, University of Alabama at Birmingham. PDBid 1UBQ.]