1hdf

Evolution of the eye lens beta-gamma-crystallin domain fold

spinqualitylabelsall models 1hdf, resolution 2.35Å Show:Asymmetric Unit Biological Assembly Drag the structure with the mouse to rotate   Export Animated Image   Print3D Structural highlights 1hdf is a 2 chain structure with sequence from Physarum polycephalum. Full crystallographic information is available from OCA. For a guided tour on the structure components use FirstGlance. Method: X-ray diffraction, Resolution 2.35Å Ligands: CA, MSE Resources: FirstGlance, OCA, PDBe, RCSB, PDBsum, ProSAT Function SR3A_PHYPO Structural protein. Evolutionary Conservation Check, as determined by ConSurfDB. You may read the explanation of the method and the full data available from ConSurf. Publication Abstract from PubMed BACKGROUND: The betagamma-crystallins belong to a superfamily of two-domain proteins found in vertebrate eye lenses, with distant relatives occurring in microorganisms. It has been considered that an eukaryotic stress protein, spherulin 3a, from the slime mold Physarum polycephalum shares a common one-domain ancestor with crystallins, similar to the one-domain 3-D structure determined by NMR. RESULTS: The X-ray structure of spherulin 3a shows it to be a tight homodimer, which is consistent with ultracentrifugation studies. The (two-motif) domain fold contains a pair of calcium binding sites very similar to those found in a two-domain prokaryotic betagamma-crystallin fold family member, Protein S. Domain pairing in the spherulin 3a dimer is two-fold symmetric, but quite different in character from the pseudo-two-fold pairing of domains in betagamma-crystallins. There is no evidence that the spherulin 3a single domain can fold independently of its partner domain, a feature that may be related to the absence of a tyrosine corner. CONCLUSION: Although it is accepted that the vertebrate two-domain betagamma-crystallins evolved from a common one-domain ancestor, the mycetezoan single-domain spherulin 3a, with its unique mode of domain pairing, is likely to be an evolutionary offshoot, perhaps from as far back as the one-motif ancestral stage. The spherulin 3a protomer stability appears to be dependent on domain pairing. Spherulin-like domain sequences that are found within bacterial proteins associated with virulence are likely to bind calcium. Crystal structure of the calcium-loaded spherulin 3a dimer sheds light on the evolution of the eye lens betagamma-crystallin domain fold.,Clout NJ, Kretschmar M, Jaenicke R, Slingsby C Structure. 2001 Feb 7;9(2):115-24. PMID:11250196 From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine.

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