Super-secondary structures involving triple-strand beta-sheets

Abstract

Triple-strand beta-sheets having up- and -down topology are widespread in proteins and occur in two forms denoted here as S-like and Z-like beta-sheets. In many cases they are included in super-secondary structures of higher order. A number of such structures is described in this paper. An important feature of these super-secondary structures is that they have a unique handedness. Another feature is that some of them only involve S-like beta-sheets and others only Z-like beta-sheets.