Thermal hysteresis protein YL-1

From Proteopedia

The beta sheet roll motif lines up the amino acid chain such that each turn interacts with a unit cell of the water ice crystal

Tenebrio molitor (Yellow mealworm beetle)

Contributes to protect body fluid from freezing at subzero temperatures. Lowers the freezing point of the hemolymph by about 2.5 degrees at a concentration of 1 mg/ml. Binds to nascent ice crystals and prevents further growth

Structural highlights

The beta-sheet roll motif sets up several lines of mostly the amino acid threonine which is able to hydrogen bond to water molecules and form a The beta-sheet roll is held together by which helps create the roll structure that allows this protein to position its amino acids in the manner shown.

References

Liou YC, Tocilj A, Davies PL, Jia Z. Mimicry of ice structure by surface hydroxyls and water of a beta-helix antifreeze protein. Nature. 2000 Jul 20;406(6793):322-4. doi: 10.1038/35018604. PMID: 10917536.