1MDU
Crystal structure of the chicken actin trimer complexed with human gelsolin segment 1 (GS-1)
Summary for 1MDU
Entry DOI | 10.2210/pdb1mdu/pdb |
Descriptor | gelsolin precursor, a-actin, CALCIUM ION, ... (6 entities in total) |
Functional Keywords | gelsolin precursor, a-actin, adenosine-5'-triphosphate, 2-amino-2-hydroxymethyl-propane-1, 3-diol, structural protein |
Biological source | Homo sapiens (human) More |
Cellular location | Cytoplasm, cytoskeleton: P06396 Isoform 2: Cytoplasm, cytoskeleton. Isoform 1: Secreted: P68139 |
Total number of polymer chains | 4 |
Total formula weight | 113780.66 |
Authors | Dawson, J.F.,Sablin, E.P.,Spudich, J.A.,Fletterick, R.J. (deposition date: 2002-08-07, release date: 2003-01-07, Last modification date: 2025-03-26) |
Primary citation | Dawson, J.F.,Sablin, E.P.,Spudich, J.A.,Fletterick, R.J. Structure of an F-actin trimer disrupted by gelsolin and implications for the mechanism of severing J.Biol.Chem., 278:1229-1238, 2003 Cited by PubMed Abstract: Stable oligomers of filamentous actin were obtained by cross-linking F-actin with 1,4-N,N'-phenylenedimaleimide and depolymerization with excess segment-1 of gelsolin. Segment-1-bound and cross-linked actin oligomers containing either two or three actin subunits were purified and shown to nucleate actin assembly. Kinetic assembly data from mixtures of monomeric actin and the actin oligomers fit a nucleation model where cross-linked actin dimer or trimer reacts with an actin monomer to produce a competent nucleus for filament assembly. We report the three-dimensional structure of the segment-1-actin hexamer containing three actin subunits, each with a tightly bound ATP. Comparative analysis of this structure with twelve other actin structures provides an atomic level explanation for the preferential binding of ATP by the segment-1-complexed actin. Although the structure of segment-1-bound actin trimer is topologically similar to the helical model of F-actin (1), it has a distorted symmetry compared with that of the helical model. This distortion results from intercalation of segment-1 between actin protomers that increase the rise per subunit and rotate each of the actin subunits relative to their positions in F-actin. We also show that segment-1 of gelsolin is able to sever actin filaments, although the severing activity of segment-1 is significantly lower than full-length gelsolin. PubMed: 12356759DOI: 10.1074/jbc.M209160200 PDB entries with the same primary citation |
Experimental method | X-RAY DIFFRACTION (2.2 Å) |
Structure validation
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