Crystal Structure of β-Helical Antifreeze Protein Points to a General Ice Binding Model
2002; Elsevier BV; Volume: 10; Issue: 5 Linguagem: Inglês
10.1016/s0969-2126(02)00745-1
ISSN1878-4186
AutoresE.K. Leinala, Peter L. Davies, Zongchao Jia,
Tópico(s)Insect and Arachnid Ecology and Behavior
ResumoReported here is the 2.3 Å resolution crystal structure of spruce budworm (Choristoneura fumiferana) antifreeze protein (CfAFP), solved by single anomalous scattering. The structure reveals an extremely regular left-handed β-helical platform consisting of 15-amino acid loops with a repetitive Thr-X-Thr motif displayed on one of the helix's three faces. This motif results in a two-dimensional array of threonine residues in an identical orientation to those in the nonhomologous, right-handed β-helical beetle AFP from Tenebrio molitor (TmAFP). The CfAFP structure led us to reevaluate our ice binding model, and the analysis of three possible modes of docking gives rise to a binding mechanism based on surface complementarity. This general mechanism is applicable to both fish and insect AFPs.
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