6R2I

Crystal structure of the SUN1-KASH5 6:6 complex

Summary for 6R2I

• Entry DOI: 10.2210/pdb6r2i/pdb
• Related: 6R15 6R16
• Descriptor: SUN domain-containing protein 1, KASH5, POTASSIUM ION, ... (4 entities in total)
• Functional Keywords: sun1, kash5, linc complex, nucleoskeleton, cytoskeleton, nuclear envelope, structural protein
• Biological source: Homo sapiens (Human); More
• Total number of polymer chains: 2
• Total formula weight: 25906.21

Authors

Gurusaran, M.,Davies, O.R. (deposition date: 2019-03-18, release date: 2020-07-15, Last modification date: 2024-01-24)

Primary citation

Gurusaran, M.,Davies, O.R.
A molecular mechanism for LINC complex branching by structurally diverse SUN-KASH 6:6 assemblies.
Elife, 10:-, 2021

PubMed Abstract: The Linker of Nucleoskeleton and Cytoskeleton (LINC) complex mechanically couples cytoskeletal and nuclear components across the nuclear envelope to fulfil a myriad of cellular functions, including nuclear shape and positioning, hearing, and meiotic chromosome movements. The canonical model is that 3:3 interactions between SUN and KASH proteins underlie the nucleocytoskeletal linkages provided by the LINC complex. Here, we provide crystallographic and biophysical evidence that SUN-KASH is a constitutive 6:6 complex in which two constituent 3:3 complexes interact head-to-head. A common SUN-KASH topology is achieved through structurally diverse 6:6 interaction mechanisms by distinct KASH proteins, including zinc-coordination by Nesprin-4. The SUN-KASH 6:6 interface provides a molecular mechanism for the establishment of integrative and distributive connections between 3:3 structures within a branched LINC complex network. In this model, SUN-KASH 6:6 complexes act as nodes for force distribution and integration between adjacent SUN and KASH molecules, enabling the coordinated transduction of large forces across the nuclear envelope.

PubMed: 33393904
DOI: 10.7554/eLife.60175

Experimental method

X-RAY DIFFRACTION (1.541 Å)