Figure 3.15. The two main secondary structural units found in proteins: (A) the α-helix, and (B) the β-sheet.

Figure 3.15The two main secondary structural units found in proteins: (A) the α-helix, and (B) the β-sheet

The polypeptide chains are shown in outline with the positions of the α-carbons indicated by small dots. The R groups have been omitted for clarity. Each structure is stabilized by hydrogen bonds between the C=O and N-H groups of different peptide bonds. The β-sheet conformation that is shown is anti-parallel, the two chains running in opposite directions. Parallel β-sheets also occur.

From: Chapter 3, Transcriptomes and Proteomes

Cover of Genomes
Genomes. 2nd edition.
Brown TA.
Oxford: Wiley-Liss; 2002.
Copyright © 2002, Garland Science.

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