1V49

Solution structure of microtubule-associated protein light chain-3

Summary for 1V49

• Entry DOI: 10.2210/pdb1v49/pdb
• NMR Information: BMRB: 5958
• Descriptor: Microtubule-associated proteins 1A/1B light chain 3B (1 entity in total)
• Functional Keywords: ubiquitin fold, structural protein
• Biological source: Homo sapiens (human)
• Cellular location: Cytoplasm, cytoskeleton: Q9GZQ8
• Total number of polymer chains: 1
• Total formula weight: 14150.28

Authors

Kouno, T.,Mizuguchi, M.,Tanida, I.,Ueno, T.,Kominami, E.,Kawano, K. (deposition date: 2003-11-11, release date: 2004-12-28, Last modification date: 2023-12-27)

Primary citation

Kouno, T.,Mizuguchi, M.,Tanida, I.,Ueno, T.,Kanematsu, T.,Mori, Y.,Shinoda, H.,Hirata, M.,Kominami, E.,Kawano, K.
Solution structure of microtubule-associated protein light chain 3 and identification of its functional subdomains.
J.Biol.Chem., 280:24610-24617, 2005

PubMed Abstract: Microtubule-associated protein (MAP) light chain 3 (LC3) is a human homologue of yeast Apg8/Aut7/Cvt5 (Atg8), which is essential for autophagy. MAP-LC3 is cleaved by a cysteine protease to produce LC3-I, which is located in cytosolic fraction. LC3-I, in turn, is converted to LC3-II through the actions of E1- and E2-like enzymes. LC3-II is covalently attached to phosphatidylethanolamine on its C terminus, and it binds tightly to autophagosome membranes. We determined the solution structure of LC3-I and found that it is divided into N- and C-terminal subdomains. Additional analysis using a photochemically induced dynamic nuclear polarization technique also showed that the N-terminal subdomain of LC3-I makes contact with the surface of the C-terminal subdomain and that LC3-I adopts a single compact conformation in solution. Moreover, the addition of dodecylphosphocholine into the LC3-I solution induced chemical shift perturbations primarily in the C-terminal subdomain, which implies that the two subdomains have different sensitivities to dodecylphosphocholine micelles. On the other hand, deletion of the N-terminal subdomain abolished binding of tubulin and microtubules. Thus, we showed that two subdomains of the LC3-I structure have distinct functions, suggesting that MAP-LC3 can act as an adaptor protein between microtubules and autophagosomes.

PubMed: 15857831
DOI: 10.1074/jbc.M413565200

Experimental method

SOLUTION NMR