1a0k
PROFILIN I FROM ARABIDOPSIS THALIANA
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OverviewOverview
BACKGROUND: Profilins are small eukaryotic proteins involved in modulating, the assembly of actin microfilaments in the cytoplasm. They are able to, bind both phosphatidylinositol-4,5-bisphosphate and poly-L-proline (PLP), and thus play a critical role in signaling pathways. Plant profilins are, of interest because immunological cross-reactivity between pollen and, human profilin may be the cause of hay fever and broad allergies to, pollens. RESULTS: The determination of the Arabidopsis thaliana profilin, isoform I structure, using multiwavelength anomalous diffraction (MAD) to, obtain structure-factor phases, is reported here. The structure of, Arabidopsis profilin is similar to that of previously determined profilin, structures. Conserved amino acid residues in profilins from plants, mammals, and lower eukaryotes are critically important in dictating the, geometry of the PLP-binding site and the overall polypeptide fold. The, main feature distinguishing plant profilins from other profilins is a, solvent-filled pocket located in the most variable region of the fold., CONCLUSIONS: Comparison of the structures of SH3 domains with those of, profilins from three distinct sources suggests that the mode of PLP, binding may be similar. A comparison of three profilin structures from, different families reveals only partial conservation of the actin-binding, surface. The proximity of the semi-conserved actin-binding site and the, binding pocket characteristic of plant profilins suggests that epitopes, encompassing both features are responsible for the cross-reactivity of, antibodies between human and plant profilins thought to be responsible for, type I allergies.
About this StructureAbout this Structure
1A0K is a Single protein structure of sequence from Arabidopsis thaliana. Structure known Active Sites: AIN, GOL and PLY. Full crystallographic information is available from OCA.
ReferenceReference
The crystal structure of a major allergen from plants., Thorn KS, Christensen HE, Shigeta R, Huddler D, Shalaby L, Lindberg U, Chua NH, Schutt CE, Structure. 1997 Jan 15;5(1):19-32. PMID:9016723
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