Atomic structures of low-complexity protein segments reveal kinked β sheets that assemble networks

Abstract

Interactions of LARKS protein domains More than 1500 human proteins contain long, disordered stretches of “low complexity”—strings of just a few of the 20 common amino acids. The functions of these low-complexity domains have been unclear. Hughes et al. present atomic-resolution structures that suggest that short segments of two such domains can bind weakly to each other by forming a pair of kinked β-sheets. Because aromatic amino acid side chains stabilize these interactions, the interacting motifs are termed LARKS, for low-complexity, aromatic-rich, kinked segments. Numerous proteins associated with membraneless organelles of biological cells contain low-complexity domains housing multiple LARKS. Science , this issue p. 698