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3chw
From Proteopedia
| 3chw, resolution 2.30Å () | |||||||||
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| Sites: | and | ||||||||
| Ligands: | , | ||||||||
| Non-Standard Residues: | |||||||||
| Gene: | pfn1 (Homo sapiens) | ||||||||
| Related: | 2pav, 2ci5, 2cip | ||||||||
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| Resources: | FirstGlance, OCA, PDBsum, RCSB | ||||||||
| Coordinates: | save as pdb, mmCIF, xml | ||||||||
Contents |
Complex of Dictyostelium discoideum Actin with Profilin and the Last Poly-Pro of Human VASP
On starvation, Dictyostelium cells aggregate to form multicellular fruiting bodies containing spores that germinate when transferred to nutrient-rich medium. This developmental cycle correlates with the extent of actin phosphorylation at Tyr-53 (pY53-actin), which is low in vegetative cells but high in viable mature spores. Here we describe high-resolution crystal structures of pY53-actin and unphosphorylated actin in complexes with gelsolin segment 1 and profilin. In the structure of pY53-actin, the phosphate group on Tyr-53 makes hydrogen-bonding interactions with residues of the DNase I-binding loop (D-loop) of actin, resulting in a more stable conformation of the D-loop than in the unphosphorylated structures. A more rigidly folded D-loop may explain some of the previously described properties of pY53-actin, including its increased critical concentration for polymerization, reduced rates of nucleation and pointed end elongation, and weak affinity for DNase I. We show here that phosphorylation of Tyr-53 inhibits subtilisin cleavage of the D-loop and reduces the rate of nucleotide exchange on actin. The structure of profilin-Dictyostelium-actin is strikingly similar to previously determined structures of profilin-beta-actin and profilin-alpha-actin. By comparing this representative set of profilin-actin structures with other structures of actin, we highlight the effects of profilin on the actin conformation. In the profilin-actin complexes, subdomains 1 and 3 of actin close around profilin, producing a 4.7 degrees rotation of the two major domains of actin relative to each other. As a result, the nucleotide cleft becomes moderately more open in the profilin-actin complex, probably explaining the stimulation of nucleotide exchange on actin by profilin.
Modulation of actin structure and function by phosphorylation of Tyr-53 and profilin binding., Baek K, Liu X, Ferron F, Shu S, Korn ED, Dominguez R, Proc Natl Acad Sci U S A. 2008 Aug 8. PMID:18689676
From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine.
About this Structure
3chw is a 3 chain structure of Actin with sequence from Dictyostelium discoideum and Homo sapiens. Full crystallographic information is available from OCA.
See Also
Reference
- Baek K, Liu X, Ferron F, Shu S, Korn ED, Dominguez R. Modulation of actin structure and function by phosphorylation of Tyr-53 and profilin binding. Proc Natl Acad Sci U S A. 2008 Aug 8. PMID:18689676
Categories: Dictyostelium discoideum | Homo sapiens | Baek, K. | Dominguez, R. | Acetylation | Actin | Actin-binding | Atp-binding | Cell junction | Cell projection | Coiled coil | Cytoplasm | Cytoskeleton | Membrane | Methyl histidine | Nucleotide-binding | Phosphoprotein | Poly-proline | Profilin | Sh3-binding | Structural protein | Ternary complex | Vasp
