The nonhelical structure of antifreeze protein type III.
Antifreeze proteins (AFPs) are present in the blood of some marine fishes and inhibit the growth of ice crystals at subzero temperatures by adsorption to the ice lattice. The solution structure of a Type III AFP was determined by two-dimensional nuclear magnetic resonance spectroscopy. These measurements indicate that this 66-residue protein has an unusual fold in which eight beta strands form two sheets of three antiparallel strands and one sheet of two antiparallel strands, and the triple-stranded sheets are packed orthogonally into a beta sandwich. This structure is completely different from the amphipathic, helical structure observed for Type I AFPs.
Sönnichsen
F D
FD
Protein Engineering Network of Centres of Excellence, University of Alberta, Edmonton, Canada.
Sykes
B D
BD
Chao
H
H
Davies
P L
PL
D000595:Amino Acid Sequence; D000818:Animals; D021301:Antifreeze Proteins; D003001:Cloning, Molecular; D004926:Escherichia coli / Q000235:genetics; D005399:Fishes; D005615:Freezing; D005813:Genes, Synthetic; D006023:Glycoproteins / Q000737:chemistry* / Q000235:genetics; D009682:Magnetic Resonance Spectroscopy / Q000379:methods; D008958:Models, Molecular; D008969:Molecular Sequence Data; D011487:Protein Conformation; D017510:Protein Folding; D017433:Protein Structure, Secondary; D011994:Recombinant Proteins / Q000737:chemistry
D021301:Antifreeze Proteins; D006023:Glycoproteins; D011994:Recombinant Proteins