02697nas a2200241   4500008004100000022001400041245015300055210006900208260008600277300001400363490000700377520171200384653002402096653002902120653003702149653002202186653002602208100002202234700002402256700001902280700002802299856012802327       2015                        eng d  a0739-110200aDistinct molecular features facilitating ice-binding mechanisms in hyperactive antifreeze proteins closely related to an Antarctic sea ice bacterium0 aDistinct molecular features facilitating icebinding mechanisms i  a530 WALNUT STREET, STE 850, PHILADELPHIA, PA 19106 USAbTAYLOR & FRANCIS INCcJUL  a1424-14410 v333 a<p>Antifreeze proteins or ice-binding proteins (IBPs) facilitate the survival of certain cellular organisms in freezing environment by inhibiting the growth of ice crystals in solution. Present study identifies orthologs of the IBP of Colwellia sp. SLW05, which were obtained from a wide range of taxa. Phylogenetic analysis on the basis of conserved regions (predicted as the `ice-binding domain' [IBD]) present in all the orthologs, separates the bacterial and archaeal orthologs from that of the eukaryotes'. Correspondence analysis pointed out that the bacterial and archaeal IBDs have relatively higher average hydrophobicity than the eukaryotic members. IBDs belonging to bacterial as well as archaeal AFPs contain comparatively more strands, and therefore are revealed to be under higher evolutionary selection pressure. Molecular docking studies prove that the ice crystals form more stable complex with the bacterial as well as archaeal proteins than the eukaryotic orthologs. Analysis of the docked structures have traced out the ice-binding sites (IBSs) in all the orthologs which continue to facilitate ice-binding activity even after getting mutated with respect to the well-studied IBSs of Typhula ishikariensis and notably, all these mutations performing ice-binding using `anchored clathrate mechanism' have been found to prefer polar and hydrophilic amino acids. Horizontal gene transfer studies point toward a strong selection pressure favoring independent evolution of the IBPs in some polar organisms including prokaryotes as well as eukaryotes because these proteins facilitate the polar organisms to acclimatize to the adversities in their niche, thus safeguarding their existence.</p>10aantifreeze proteins10ahorizontal gene transfer10aice-recrystallization inhibition10aMolecular docking10aPhylogenetic analysis1 aBanerjee, Rachana1 aChakraborti, Pratim1 aBhowmick, Rupa1 aMukhopadhyay, Subhasish  uhttps://library.ncl.res.in/content/distinct-molecular-features-facilitating-ice-binding-mechanisms-hyperactive-antifreeze-1