title: An extracellular ice-binding glycoprotein from an Arctic psychrophilic yeast.
abstract: A psychrophilic yeast was isolated from an Arctic pond and its culture supernatant showed ice-binding activity. This isolate, identified as Leucosporidium sp. based on an analysis of the D1/D2 and ITS regions of its ribosomal DNA, produced a secretory ice-binding protein (IBP). Yeast IBP was purified from the culture medium to near homogeneity by the ice affinity method and appeared to be glycosylated with a molecular mass of approximately 26 kDa. In addition, the yeast IBP was shown to have thermal hysteresis (TH) and recrystallization inhibition (RI) activities. The full-length cDNA for yeast IBP was determined and was found to encode a 261 amino acid protein with molecular weight of 26.8 kDa that includes an N-terminal signal peptide and one potential N-glycosylation site. The deduced protein showed high sequence identity with other IBPs and hypothetical IBPs from fungi, diatoms, and bacteria, clustering with a class of ice-active proteins.
authors.affiliation: Division of Polar Biology and Ocean Sciences, Korea Polar Research Institute, Incheon, Republic of Korea.
authors.forename: Jong Kyu
authors.initials: JK
authors.lastname: Lee
authors.forename: Kyoung Sun
authors.initials: KS
authors.lastname: Park
authors.forename: Seungil
authors.initials: S
authors.lastname: Park
authors.forename: Hyun
authors.initials: H
authors.lastname: Park
authors.forename: Young Hwan
authors.initials: YH
authors.lastname: Song
authors.forename: Sung-Ho
authors.initials: SH
authors.lastname: Kang
authors.forename: Hak Jun
authors.initials: HJ
authors.lastname: Kim
mesh_terms: D000595:Amino Acid Sequence; D021301:Antifreeze Proteins / Q000302:isolation & purification / Q000378:metabolism*; D001110:Arctic Regions; D001483:Base Sequence; D001487:Basidiomycota / Q000235:genetics / Q000302:isolation & purification / Q000378:metabolism*; D003001:Cloning, Molecular; D017931:DNA Primers / Q000235:genetics; D004271:DNA, Fungal / Q000235:genetics; D004275:DNA, Ribosomal / Q000235:genetics; D005618:Fresh Water / Q000382:microbiology; D005656:Fungal Proteins / Q000302:isolation & purification / Q000378:metabolism*; D005800:Genes, Fungal; D046448:Ice Cover / Q000382:microbiology; D008969:Molecular Sequence Data; D010802:Phylogeny; D017386:Sequence Homology, Amino Acid; D014871:Water Microbiology
chemical_list: D021301:Antifreeze Proteins; D017931:DNA Primers; D004271:DNA, Fungal; D004275:DNA, Ribosomal; D005656:Fungal Proteins