6N1Z

Importin-9 bound to H2A-H2B

Summary for 6N1Z

• Entry DOI: 10.2210/pdb6n1z/pdb
• Descriptor: Importin-9, Histone H2A, Histone H2B 1.1, ... (4 entities in total)
• Functional Keywords: importin-9, karyopherin, histone, h2a, h2b, histone chaperone, ran gtpase, nucleosome, nls, nuclear pore complex., transport protein
• Biological source: Homo sapiens (Human); More
• Total number of polymer chains: 6
• Total formula weight: 287655.41

Authors

Tomchick, D.R.,Chook, Y.M.,Padavannil, A. (deposition date: 2018-11-12, release date: 2019-03-20, Last modification date: 2024-03-13)

Primary citation

Padavannil, A.,Sarkar, P.,Kim, S.J.,Cagatay, T.,Jiou, J.,Brautigam, C.A.,Tomchick, D.R.,Sali, A.,D'Arcy, S.,Chook, Y.M.
Importin-9 wraps around the H2A-H2B core to act as nuclear importer and histone chaperone.
Elife, 8:-, 2019

PubMed Abstract: We report the crystal structure of nuclear import receptor Importin-9 bound to its cargo, the histones H2A-H2B. Importin-9 wraps around the core, globular region of H2A-H2B to form an extensive interface. The nature of this interface coupled with quantitative analysis of deletion mutants of H2A-H2B suggests that the NLS-like sequences in the H2A-H2B tails play a minor role in import. Importin-9•H2A-H2B is reminiscent of interactions between histones and histone chaperones in that it precludes H2A-H2B interactions with DNA and H3-H4 as seen in the nucleosome. Like many histone chaperones, which prevent inappropriate non-nucleosomal interactions, Importin-9 also sequesters H2A-H2B from DNA. Importin-9 appears to act as a storage chaperone for H2A-H2B while escorting it to the nucleus. Surprisingly, RanGTP does not dissociate Importin-9•H2A-H2B but assembles into a RanGTP•Importin-9•H2A-H2B complex. The presence of Ran in the complex, however, modulates Imp9-H2A-H2B interactions to facilitate its dissociation by DNA and assembly into a nucleosome.

PubMed: 30855230
DOI: 10.7554/eLife.43630

Experimental method

X-RAY DIFFRACTION (2.7 Å)