Structure of a bacterial ice binding protein with two faces of interaction with ice. (10th April 2018)

• Record Type: Journal Article
• Authors: Mangiagalli, Marco; Sarusi, Guy; Kaleda, Aleksei; Bar Dolev, Maya; Nardone, Valentina; Vena, Vittoria Federica; Braslavsky, Ido; Lotti, Marina; Nardini, Marco
• Is Part Of: FEBS journal. Volume 285:Number 9(2018)
• Page Start: 1653
• Page End: 1666
• Publication Date: 2018-04-10
• Subjects: cold adaptation -- DUF3494 -- IBP‐1 fold -- ice recrystallization inhibition -- thermal hysteresis; Biochemistry -- Periodicals; Molecular biology -- Periodicals; Pathology, Molecular -- Periodicals; 572
• DOI: 10.1111/febs.14434
• Languages: English
• ISSNs: 1742-464X

Abstract

Abstract : Ice‐binding proteins (IBPs) 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 IBPs, 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 number6EIO . Abstract : The three‐dimensional structure of Efc IBP, an ice‐binding protein, was solved. The structure consists of a β‐solenoid with a triangular cross‐section and exposes to the solvent three surfaces, named A, B and C faces. Docking experiments and site‐directed mutagenesis show that Efc IBP binds ice crystals through both the B and the C faces.