User:Karsten Theis/turns
From Proteopedia
(Difference between revisions)
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===Excercise 1=== | ===Excercise 1=== | ||
| - | Try to use the buttons to make a type 1 turn with the features shown below. Are there any clashes? How is the different from an alpha helix (where all carbonyl groups are pointing in the same direction)? | + | Try to use the buttons to make a type 1 turn with the features shown below. This is the most common beta turn (about one third are of this type). Are there any clashes? How is the different from an alpha helix (where all carbonyl groups are pointing in the same direction)? |
[[Image:Beta_turn_type_I.png|500px]] | [[Image:Beta_turn_type_I.png|500px]] | ||
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===Excercise 2=== | ===Excercise 2=== | ||
| - | And now try to get a type I prime conformation, as shown below. Hint: the pepflip button might serve as a bit of a shortcut. Why is that? Are there any clashes? If you had to choose, would you place a glycine at position 2 or position 3? | + | And now try to get a type I prime conformation, as shown below. This turn is rare (about 4% of beta turns are of this type). Hint: the pepflip button might serve as a bit of a shortcut. Why is that? Are there any clashes? If you had to choose, would you place a glycine at position 2 or position 3? |
[[Image:Beta_turn_type_I_prime.png|500px]] | [[Image:Beta_turn_type_I_prime.png|500px]] | ||
Revision as of 19:20, 8 February 2025
A beta turn is a secondary structure element consisting of four consecutive amino acids (or three consecutive peptide planes). The geometry of turns correspond to a change in the direction of the polypeptide backbone, with a short distance between the first and fourth alpha carbon. This allows them to connect alpha helices and beta strands at the surface of a globular protein. Of the six main chain hydrogen bonding partners of a turn, a maximum of two are engaged in hydrogen bonding, and turns are rarely found in the hydrophobic core.
Exploring turns
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References
- ↑ de Brevern AG. A Perspective on the (Rise and Fall of) Protein β-Turns. Int J Mol Sci. 2022 Oct 14;23(20):12314. PMID:36293166 doi:10.3390/ijms232012314
