2oan

Structure of oxidized beta-actinStructure of oxidized beta-actin

Structural highlights 2oan is a 4 chain structure with sequence from Bos taurus. Full crystallographic information is available from OCA. For a guided tour on the structure components use FirstGlance. Method: X-ray diffraction, Resolution 2.606Å Ligands: , , , Resources: FirstGlance, OCA, PDBe, RCSB, PDBsum, ProSAT Function ACTB_BOVIN Actins are highly conserved proteins that are involved in various types of cell motility and are ubiquitously expressed in all eukaryotic cells. Publication Abstract from PubMed An essential consequence of growth factor-mediated signal transduction is the generation of intracellular H(2)O(2). It operates as a second messenger in the control of actin microfilament dynamics, causing rapid and dramatic changes in the morphology and motile activity of stimulated cells. Little is understood about the molecular mechanisms causing these changes in the actin system. Here, it is shown that H(2)O(2) acts directly upon several levels of this system, and some of the mechanistic effects are detailed. We describe the impact of oxidation on the polymerizability of non-muscle beta/gamma-actin and compare with that of muscle alpha-actin. Oxidation of beta/gamma-actin can cause a complete loss of polymerizability, crucially, reversible by the thioredoxin system. Further, oxidation of the actin impedes its interaction with profilin and causes depolymerization of filamentous actin. The effects of oxidation are critically dependent on the nucleotide state and the concentration of Ca(2+). We have determined the crystal structure of oxidized beta-actin to a resolution of 2.6 A. The arrangement in the crystal implies an antiparallel homodimer connected by an intermolecular disulfide bond involving cysteine 374. Our data indicate that this dimer forms under non-polymerizing and oxidizing conditions. We identify oxidation of cysteine 272 in the crystallized actin dimer, likely to a cysteine sulfinic acid. In beta/gamma-actin, this is the cysteine residue most reactive towards H(2)O(2) in solution, and we suggest plausible structural determinants for its reactivity. No other oxidative modification was obvious in the structure, highlighting the specificity of the oxidation by H(2)O(2). Possible consequences of the observed effects in a cellular context and their potential relevance are discussed. Molecular and structural basis for redox regulation of beta-actin.,Lassing I, Schmitzberger F, Bjornstedt M, Holmgren A, Nordlund P, Schutt CE, Lindberg U J Mol Biol. 2007 Jul 6;370(2):331-48. Epub 2007 May 4. PMID:17521670 From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine. See Also Actin 3D structures

spinqualitylabelsall models 2oan, resolution 2.61Å Show:Asymmetric Unit Biological Assembly Drag the structure with the mouse to rotate   Export Animated Image