Local sequence of protein β-strands influences twist and bend angles.
β-Sheet twisting is thought to be mainly determined by interstrand hydrogen bonds with little contribution from side chains, but some proteins have large, flat β-sheets, suggesting that side chains influence β-structures. We therefore investigated the relationship between amino acid composition and twists or bends of β-strands. We calculated and statistically analyzed the twist and bend angles of short frames of β-strands in known protein structures. The most frequent twist angles were strongly negatively correlated with the proportion of hydrophilic amino acid residues. The majority of hydrophilic residues (except serine and threonine) were found in the edge regions of β-strands, suggesting that the side chains of these residues likely do not affect β-strand structure. In contrast, the majority of serine, threonine, and asparagine side-chains in β-strands made contacts with a nitrogen atom of the main chain, suggesting that these residues suppress β-strand twisting.
['Fujiwara|Kazuo|K|', 'Ebisawa|Shinichi|S|', 'Watanabe|Yuka|Y|', 'Toda|Hiromi|H|', 'Ikeguchi|Masamichi|M|']
D000595:Amino Acid Sequence D000596:Amino Acids D006860:Hydrogen Bonding D057927:Hydrophobic and Hydrophilic Interactions D008958:Models, Molecular D017433:Protein Structure, Secondary D011506:Proteins
interstrand hydrogen bond effect of side chain to the β-sheet large flat β-sheet protein design statistical analysis