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Structure of a bacterial ice binding protein with two faces of interaction with ice
Author(s) -
Mangiagalli Marco,
Sarusi Guy,
Kaleda Aleksei,
Bar Dolev Maya,
Nardone Valentina,
Vena Vittoria Federica,
Braslavsky Ido,
Lotti Marina,
Nardini Marco
Publication year - 2018
Publication title -
the febs journal
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.981
H-Index - 204
eISSN - 1742-4658
pISSN - 1742-464X
DOI - 10.1111/febs.14434
Subject(s) - binding site , crystallography , chemistry , ice crystals , ice core , sea ice , docking (animal) , biophysics , chemical physics , biology , physics , geology , biochemistry , oceanography , meteorology , medicine , nursing
Ice‐binding proteins ( IBP s) contribute to the survival of many living beings at subzero temperature by controlling the formation and growth of ice crystals. This work investigates the structural basis of the ice‐binding properties of Efc IBP, obtained from Antarctic bacteria. Efc IBP is endowed with a unique combination of thermal hysteresis and ice recrystallization inhibition activity. The three‐dimensional structure, solved at 0.84 Å resolution, shows that Efc IBP belongs to the IBP ‐1 fold family, and is organized in a right‐handed β‐solenoid with a triangular cross‐section that forms three protein surfaces, named A, B, and C faces. However, Efc IBP diverges from other IBP ‐1 fold proteins in relevant structural features including the lack of a ‘capping’ region on top of the β‐solenoid, and in the sequence and organization of the regions exposed to ice that, in Efc IBP, reveal the presence of threonine‐rich ice‐binding motifs. Docking experiments and site‐directed mutagenesis pinpoint that Efc IBP binds ice crystals not only via its B face, as common to other IBP s, but also via ice‐binding sites on the C face. Database Coordinates and structure factors have been deposited in the Protein Data Bank under accession number 6EIO .