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Beta strand secondary structure

In this conformation, the peptide backbone is extended, with the amino acid sidechains alternating towards both sides.

(to simplify, H atoms are not shown)

Hiding the sidechains we can see that the backbone describes a zigzag.

An important aspect of this extended conformation is that several beta strands, arranged in parallel, can associate among them by means of interchain hydrogen bonds (••••••) between the carbonyl groups and the nitrogens in the peptide bonds.

>C=O••••••H–N<

In this way, a beta sheet or beta pleated sheet can be formed   (move it to see it well)

The sidechains stick out at both sides of the sheet.

Each amino acid in its own color:
Asn- Arg- Asn- Thr- Ala
Ser- Thr- Asp- Tyr- Gly

In models for large proteins, the portions with beta strand conformation are usually rendered in a simplified “cartoon” form as a ribbon with arrowhead (this pointing towards the C-terminal end); 2 styles: .