3UNP

Structure of human SUN2 SUN domain

Summary for 3UNP

• Entry DOI: 10.2210/pdb3unp/pdb
• Descriptor: SUN domain-containing protein 2, ACETYL GROUP (3 entities in total)
• Functional Keywords: trimer, nuclear envelope, sun domain, kash domain, linc complex, nuclear migration, transport protein
• Biological source: Homo sapiens (human)
• Cellular location: Nucleus inner membrane; Single-pass type II membrane protein: Q9UH99
• Total number of polymer chains: 1
• Total formula weight: 22929.73

Authors

Zhou, Z.C.,Greene, M.I. (deposition date: 2011-11-16, release date: 2011-12-21, Last modification date: 2024-03-20)

Primary citation

Zhou, Z.C.,Du, X.,Cai, Z.,Song, X.,Zhang, H.,Mizuno, T.,Suzuki, E.,Yee, M.R.,Berezov, A.,Murali, R.,Wu, S.-L.,Karger, B.L.,Greene, M.I.,Wang, Q.
Structure of Sad1-UNC84 homology (SUN) domain defines features of molecular bridge in nuclear envelope
J.Biol.Chem., 287:5317-5326, 2012

PubMed Abstract: The SUN (Sad1-UNC-84 homology) domain is conserved in a number of nuclear envelope proteins involved in nuclear migration, meiotic telomere tethering, and antiviral responses. The LINC (linker of nucleoskeleton and cytoskeleton) complex, formed by the SUN and the nesprin proteins at the nuclear envelope, serves as a mechanical linkage across the nuclear envelope. Here we report the crystal structure of the SUN2 protein SUN domain, which reveals a homotrimer. The SUN domain is sufficient to mediate binding to the KASH (Klarsicht, ANC-1, and Syne homology) domain of nesprin 2, and the regions involved in the interaction have been identified. Binding of the SUN domain to the KASH domain is abolished by deletion of a region important for trimerization or by point mutations associated with nuclear migration failure. We propose a model of the LINC complex, where the SUN and the KASH domains form a higher ordered oligomeric network in the nuclear envelope. These findings provide the structural basis for understanding the function and the regulation of the LINC complex.

PubMed: 22170055
DOI: 10.1074/jbc.M111.304543

Experimental method

X-RAY DIFFRACTION (2.39 Å)