The grass Lolium perenne produces an ice-binding protein (LpIBP) that helps this perennial tolerate freezing by inhibiting the recrystallization of ice [1]. Ice-binding proteins (IBPs) are also produced by freeze-avoiding organisms to halt the growth of ice and are better known as antifreeze proteins (AFPs) [1]. The ice-binding site (IBS) is formed by a flat beta-sheet on one surface of the beta-roll [1]. This region folds as a left-handed beta-helix. Each of the eight beta-helical coils is composed of two seven-residue tandem repeats with a consensus sequence XXNXVXG where X is a solvent-exposed residue, typically with a polar side chain [1].

1: Antifreeze protein from freeze-tolerant grass has a beta-roll fold with an irregularly structured ice-binding site. Middleton AJ, Marshall CB, Faucher F, Bar-Dolev M, Braslavsky I, Campbell RL, Walker VK, Davies PL; J Mol Biol. 2012;416:713-724. PMID:22306740