3FM7

Quaternary Structure of Drosophila melanogaster IC/Tctex-1/LC8; Allosteric Interactions of Dynein Light Chains with Dynein Intermediate Chain

Summary for 3FM7

• Entry DOI: 10.2210/pdb3fm7/pdb
• Descriptor: Dynein light chain Tctex-type, Dynein intermediate chain, cytosolic, Dynein light chain 1, cytoplasmic (3 entities in total)
• Functional Keywords: cytoplasmic dynein, light chain tctex-1, tctex, light chain 8, lc8, intermediate chain, ic, dynein cargo attachment complex, dynein light chain, quaternary structure, dynein, microtubule, motor protein, lysosome, membrane, nucleus, wd repeat, contractile protein
• Biological source: Drosophila melanogaster (Fruit fly); More
• Cellular location: Cytoplasm, cytoskeleton (Probable): Q94524; Cytoplasm, cytoskeleton. Isoform 2c: Lysosome membrane; Peripheral membrane protein; Cytoplasmic side. Isoform 2a: Nucleus membrane; Peripheral membrane protein; Cytoplasmic side. Isoform 2b: Nucleus membrane; Peripheral membrane protein; Cytoplasmic side: Q24246; Cytoplasm, cytoskeleton: Q24117
• Total number of polymer chains: 6
• Total formula weight: 51868.55

Authors

Hall, J.D.,Karplus, P.A.,Barbar, E.J. (deposition date: 2008-12-19, release date: 2009-09-15, Last modification date: 2023-09-06)

Primary citation

Hall, J.,Karplus, P.A.,Barbar, E.
Multivalency in the assembly of intrinsically disordered Dynein intermediate chain.
J.Biol.Chem., 284:33115-33121, 2009

PubMed Abstract: Dynein light chains are thought to increase binding efficiency of dynein intermediate chain to both dynein heavy chain and dynactin, but their exact role is not clear. Isothermal titration calorimetry and x-ray crystallography reported herein indicate that multivalency effects underlie efficient dynein assembly and regulation. For a ternary complex of a 60-amino acid segment of dynein intermediate chain (IC) bound to two homodimeric dynein light chains Tctex1 and LC8, there is a 50-fold affinity enhancement for the second light chain binding. For a designed IC construct containing two LC8 sites, observed the 1000-fold enhancement reflects a remarkably pure entropic chelate effect of a magnitude commensurate with theoretical predictions. The lower enhancement in wild-type IC is attributed to unfavorable free energy changes associated with incremental interactions of IC with Tctex1. Our results show assembled dynein IC as an elongated, flexible polybivalent duplex, and suggest that polybivalency is an important general mechanism for constructing stable yet reversible and functionally versatile complexes.

PubMed: 19759397
DOI: 10.1074/jbc.M109.048587

Experimental method

X-RAY DIFFRACTION (3.5 Å)