This family includes members found in bacteria, fungi and archaea, many of which are ice-binding proteins (IBPs) [1]. In Antarctic bacterium Flavobacterium frigoris PS1, FfIBP is an ice-binding protein that inhibits ice growth through direct interaction with ice crystals to permit the survival of polar organisms in extremely cold environments [2]. In arctic yeast Leucosporidium sp, LeIBP, an ice-binding protein, can lower the freezing point below the melting point once it binds to ice [3]. Family members also have a single completely conserved glycine residue that may be functionally important.

1: Ice-binding proteins and the 'domain of unknown function' 3494 family. Vance TDR, Bayer-Giraldi M, Davies PL, Mangiagalli M; FEBS J. 2019;286:855-873. PMID:30680879

2: Structure-based characterization and antifreeze properties of a hyperactive ice-binding protein from the Antarctic bacterium Flavobacterium frigoris PS1. Do H, Kim SJ, Kim HJ, Lee JH; Acta Crystallogr D Biol Crystallogr. 2014;70:1061-1073. PMID:24699650

3: Structural basis for antifreeze activity of ice-binding protein from arctic yeast. Lee JH, Park AK, Do H, Park KS, Moh SH, Chi YM, Kim HJ; J Biol Chem. 2012;287:11460-11468. PMID:22303017