Levels of Protein Organization
A protein's primary structure is defined as the amino acid sequence of its polypeptide chain; secondary structure is the local spatial arrangement of a polypeptide's backbone (main chain) atoms; tertiary structure refers to the three-dimensional structure of an entire polypeptide chain; and quaternary structure is the three-dimensional arrangement of the subunits in a multisubunit protein. In this series of pages we examine the different levels of protein organization. We also view structures in lots of ways -- Cα backbone, ball-and-stick, CPK, ribbon, spacefilling -- as well color is used to highlight different aspects of the amino acids, structure, etc. As you traverse though this module please note these aspects.
This module includes links to KiNG (Kinemage, Next Generation), which displays three-dimensional structures in an animated, interactive format. These "kinemages" (kinetic images) can be rotated, moved, and zoomed, and parts can be hidden or shown. Kinemages were originally implemented under the auspices of the Innovative Technology Fund and the Protein Society, and the programming and maintenance are done by David C. Richardson and Jane S. Richardson.
Reference: "THE KINEMAGE: A TOOL FOR SCIENTIFIC COMMUNICATION" D.C. Richardson and J.S. Richardson (1992) Protein Science 1: 3-9. Also Trends in Biochem. Sci. (1994) 19: 135-8.
Text adapted from: Demo5_4a.kin