title: Crystal structure of the NEMO ubiquitin-binding domain in complex with Lys 63-linked di-ubiquitin.
abstract: NEMO is essential for activation of the NF-kappaB signaling pathway, which is regulated by ubiquitination of proteins. The C-terminal leucine zipper of NEMO and its adjacent coiled-coil region (CC2-LZ) reportedly bind to linear ubiquitin chains with 1 microM affinity and to Lys 63-linked chains with 100 microM affinity. Here we report the crystal structure of the CC2-LZ region of mouse NEMO in complex with Lys 63-linked di-ubiquitin (K63-Ub(2)) at 2.7A resolution. The ubiquitin-binding region consists of a 130A-long helix and forms a parallel coiled-coil dimer. The Ile 44-centered hydrophobic patch of ubiquitin is recognized in the middle of the NEMO ubiquitin-binding region. NEMO interacts with each K63-Ub(2)via a single ubiquitin-binding site, consistent with low affinity binding with K63-Ub(2).
authors.affiliation: Structural Biology Laboratory, Life Science Division, Synchrotron Radiation Research Organization and Institute of Molecular and Cellular Biosciences, The University of Tokyo, Tokyo 113-0032, Japan.
authors.forename: Azusa
authors.initials: A
authors.lastname: Yoshikawa
authors.forename: Yusuke
authors.initials: Y
authors.lastname: Sato
authors.forename: Masami
authors.initials: M
authors.lastname: Yamashita
authors.forename: Hisatoshi
authors.initials: H
authors.lastname: Mimura
authors.forename: Atsushi
authors.initials: A
authors.lastname: Yamagata
authors.forename: Shuya
authors.initials: S
authors.lastname: Fukai
mesh_terms: D000595:Amino Acid Sequence; D000818:Animals; D001665:Binding Sites; D018360:Crystallography, X-Ray; D047908:Intracellular Signaling Peptides and Proteins / Q000737:chemistry* / Q000235:genetics / Q000378:metabolism; D008239:Lysine / Q000737:chemistry* / Q000378:metabolism; D051379:Mice; D008958:Models, Molecular; D008969:Molecular Sequence Data; D011485:Protein Binding; D017433:Protein Structure, Secondary; D017434:Protein Structure, Tertiary; D016415:Sequence Alignment; D025801:Ubiquitin / Q000737:chemistry* / Q000235:genetics / Q000378:metabolism
chemical_list: D047908:Intracellular Signaling Peptides and Proteins; C514981:NEMO protein, mouse; D025801:Ubiquitin; D008239:Lysine