Solution structure of the antifreeze-like domain of human sialic acid synthase.

The structure of the C-terminal antifreeze-like (AFL) domain of human sialic acid synthase was determined by NMR spectroscopy. The structure comprises one α- and two single-turn 3₁₀-helices and two β-strands, and is similar to those of the type III antifreeze proteins. Evolutionary trace analyses of the type III antifreeze protein family suggested that the class-specific residues in the human and bacterial AFL domains are important for their substrate binding, while the class-specific residues of the fish antifreeze proteins are gathered on the ice-binding surface. [ABSTRACT FROM AUTHOR]