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User:Tilman Schirmer/Sandbox 100
From Proteopedia
(→Repetitive torsion angles) |
(→Repetitive torsion angles) |
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Note: <br> | Note: <br> | ||
| - | polypeptide forms a | + | |
| + | polypeptide forms a <scene name='User:Tilman_Schirmer/Sandbox_100/Beta/4'>zig-zag</scene>zig-zag with side-chains protruding towards alternating (up, down) directions<br> | ||
| + | |||
the polypeptide main-chain is <scene name='User:Tilman_Schirmer/Sandbox_100/Beta/3'>left-twisted</scene> as can been seen when looking along the chain <br> | the polypeptide main-chain is <scene name='User:Tilman_Schirmer/Sandbox_100/Beta/3'>left-twisted</scene> as can been seen when looking along the chain <br> | ||
Revision as of 13:57, 19 March 2009
Contents |
Secondary structure of proteins
Repetitive torsion angles
|
A polypeptide chain with a repetition of identical phi-psi torsion angles yields a helical structure.
phi-psi = (180o, 180o), fully extended chain:
,
phi-psi = (-140o, 130o), extended chain:
,
; this is the β-strand conformation found in beta-sheets
Note:
polypeptide forms a zig-zag with side-chains protruding towards alternating (up, down) directions
the polypeptide main-chain is as can been seen when looking along the chain
phi-psi = (70o, 180o):
,
; note that there are clashes (where?)
phi-psi = (-60o, -40o), α-helix:
,
phi-psi = (-50o, -26o), 310 helix:
,
