3P4G
X-ray crystal structure of a hyperactive, Ca2+-dependent, beta-helical antifreeze protein from an Antarctic bacterium
Summary for 3P4G
| Entry DOI | 10.2210/pdb3p4g/pdb |
| Descriptor | Antifreeze protein, CALCIUM ION, MAGNESIUM ION, ... (5 entities in total) |
| Functional Keywords | right-handed ca2+-binding beta-helix, antifreeze protein |
| Biological source | Marinomonas primoryensis |
| Total number of polymer chains | 4 |
| Total formula weight | 135734.22 |
| Authors | Garnham, C.P.,Campbell, R.L.,Davies, P.L. (deposition date: 2010-10-06, release date: 2011-04-27, Last modification date: 2024-02-21) |
| Primary citation | Garnham, C.P.,Campbell, R.L.,Davies, P.L. Anchored clathrate waters bind antifreeze proteins to ice. Proc.Natl.Acad.Sci.USA, 108:7363-7367, 2011 Cited by PubMed Abstract: The mechanism by which antifreeze proteins (AFPs) irreversibly bind to ice has not yet been resolved. The ice-binding site of an AFP is relatively hydrophobic, but also contains many potential hydrogen bond donors/acceptors. The extent to which hydrogen bonding and the hydrophobic effect contribute to ice binding has been debated for over 30 years. Here we have elucidated the ice-binding mechanism through solving the first crystal structure of an Antarctic bacterial AFP. This 34-kDa domain, the largest AFP structure determined to date, folds as a Ca(2+)-bound parallel beta-helix with an extensive array of ice-like surface waters that are anchored via hydrogen bonds directly to the polypeptide backbone and adjacent side chains. These bound waters make an excellent three-dimensional match to both the primary prism and basal planes of ice and in effect provide an extensive X-ray crystallographic picture of the AFPice interaction. This unobstructed view, free from crystal-packing artefacts, shows the contributions of both the hydrophobic effect and hydrogen bonding during AFP adsorption to ice. We term this mode of binding the "anchored clathrate" mechanism of AFP action. PubMed: 21482800DOI: 10.1073/pnas.1100429108 PDB entries with the same primary citation |
| Experimental method | X-RAY DIFFRACTION (1.7 Å) |
Structure validation
Download full validation report
