1aj3
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SOLUTION STRUCTURE OF THE SPECTRIN REPEAT, NMR, 20 STRUCTURES
OverviewOverview
Cytoskeletal proteins belonging to the spectrin family have an elongated, structure composed of repetitive units. The three-dimensional solution, structure of the 16th repeat from chicken brain alpha-spectrin (R16) has, been determined by NMR spectroscopy and distance geometry-simulated, annealing calculations. We used a total of 1035 distance restraints, which, included 719 NOE-based values obtained by applying the ambiguous, restraints for iterative assignment (ARIA) method. In addition, we, performed a direct refinement against 1H-chemical shifts. The final, ensemble of 20 structures shows an average RMSD of 1.52 A from the mean, for the backbone atoms, excluding loops and N and C termini. R16 is made, up of three antiparallel alpha-helices separated by two loops, and folds, into a left-handed coiled-coil.The basic unit of spectrin is an, antiparallel heterodimer composed of two homologous chains, beta and, alpha. These assemble a tetramer via a mechanism that relies on the, completion of a single repeat by association of the partial repeats, located at the C terminus of the beta-chain (two helices) and at the N, terminus of the alpha-chain (one helix). This tetramer is the assemblage, able to cross-link actin filaments. Model building by homology of the, "tetramerization" repeat from human erythrocyte spectrin illuminates the, possible role of point mutations which cause hemolytic anemias.
About this StructureAbout this Structure
1AJ3 is a Single protein structure of sequence from Gallus gallus. Full crystallographic information is available from OCA.
ReferenceReference
Solution structure of the spectrin repeat: a left-handed antiparallel triple-helical coiled-coil., Pascual J, Pfuhl M, Walther D, Saraste M, Nilges M, J Mol Biol. 1997 Oct 31;273(3):740-51. PMID:9356261
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