1IO0

CRYSTAL STRUCTURE OF TROPOMODULIN C-TERMINAL HALF

Summary for 1IO0

• Entry DOI: 10.2210/pdb1io0/pdb
• Descriptor: TROPOMODULIN, ZINC ION (3 entities in total)
• Functional Keywords: lrr protein, right-handed super-helix, protein binding
• Biological source: Gallus gallus (chicken)
• Total number of polymer chains: 1
• Total formula weight: 20714.92

Authors

Krieger, I.,Kostyukova, A.,Yamashita, A.,Maeda, Y. (deposition date: 2000-12-14, release date: 2002-11-27, Last modification date: 2023-12-27)

Primary citation

Krieger, I.,Kostyukova, A.,Yamashita, A.,Nitanai, Y.,Maeda, Y.
Crystal structure of the C-terminal half of tropomodulin and structural basis of actin filament pointed-end capping.
Biophys.J., 83:2716-2725, 2002

PubMed Abstract: Tropomodulin is the unique pointed-end capping protein of the actin-tropomyosin filament. By blocking elongation and depolymerization, tropomodulin regulates the architecture and the dynamics of the filament. Here we report the crystal structure at 1.45-A resolution of the C-terminal half of tropomodulin (C20), the actin-binding moiety of tropomodulin. C20 is a leucine-rich repeat domain, and this is the first actin-associated protein with a leucine-rich repeat. Binding assays suggested that C20 also interacts with the N-terminal fragment, M1-M2-M3, of nebulin. Based on the crystal structure, we propose a model for C20 docking to the actin subunit at the pointed end. Although speculative, the model is consistent with the idea that a tropomodulin molecule competes with an actin subunit for a pointed end. The model also suggests that interactions with tropomyosin, actin, and nebulin are all possible sources of influences on the dynamic properties of pointed-end capping by tropomodulin.

PubMed: 12414704
DOI: 10.1016/S0006-3495(02)75281-8

Experimental method

X-RAY DIFFRACTION (1.45 Å)