Beta Turn In Protein

Question

[Elisa]

Dear All

I'm studying a transmembrane protein receptor. According to you what could be the role of beta-turn in loops, C-terminal or N-terminal in a TM protein?

Thanks

Answer 1

[Anima Mundi]

β-turns are supposed to be stable secondary structures promoting the formation of antiparallel β-sheets. So, I suppose its presence could stabilize β-barrels, which are tipycal transmembran structures based on antiparallel β-sheets.

[Khader Shameer]

Anima: Could you please add some relevant references - Thanks.

[Anima Mundi]

As elisa asked for opinions, I speculated a bit on β-turns' role with a syllogism: a) β-turns promote antiparallel β-sheets; b) β-barrels are based on antiparallel β-sheets; β-turns promote β-barrels. Beside this, Qamra R, Taneja B, Mande SC 2002 state: "Our study suggests that the conserved type II beta-turn and the non-polar residues in the barrel core are crucial for the folding of the protein's primary sequence into the beta-barrel conformation".