An ice-binding protein from an Antarctic sea ice bacterium.
An Antarctic sea ice bacterium of the Gram-negative genus Colwellia, strain SLW05, produces an extracellular substance that changes the morphology of growing ice. The active substance was identified as a approximately 25-kDa protein that was purified through its affinity for ice. The full gene sequence was determined and was found to encode a 253-amino acid protein with a calculated molecular mass of 26,350 Da. The predicted amino acid sequence is similar to predicted sequences of ice-binding proteins recently found in two species of sea ice diatoms and a species of snow mold. A recombinant ice-binding protein showed ice-binding activity and ice recrystallization inhibition activity. The protein is much smaller than bacterial ice-nucleating proteins and antifreeze proteins that have been previously described. The function of the protein is unknown but it may act as an ice recrystallization inhibitor to protect membranes in the frozen state.
Raymond
James A
JA
School of Life Sciences, University of Nevada, Las Vegas, NV, USA. raymond@unlv.nevada.edu
Fritsen
Christian
C
Shen
Kate
K
D034241:Alteromonadaceae / Q000235:genetics / Q000378:metabolism*; D000595:Amino Acid Sequence; D000864:Antarctic Regions; D001426:Bacterial Proteins / Q000737:chemistry / Q000235:genetics / Q000502:physiology*; D001483:Base Sequence; D007053:Ice; D008969:Molecular Sequence Data; D020539:Sequence Analysis, Protein
D001426:Bacterial Proteins; D007053:Ice