7NDY

Di-phosphorylated Barrier-to-Autointegration Factor (BAF) in complex with LEM domain of Emerin

Summary for 7NDY

• Entry DOI: 10.2210/pdb7ndy/pdb
• Descriptor: Barrier-to-autointegration factor, N-terminally processed, Emerin, 4-(2-HYDROXYETHYL)-1-PIPERAZINE ETHANESULFONIC ACID, ... (4 entities in total)
• Functional Keywords: phosphorylation complex high resolution, dna binding protein
• Biological source: Homo sapiens (Human); More
• Total number of polymer chains: 3
• Total formula weight: 41672.60

Authors

Marcelot, A.,Le Du, M.H.,Hoffmann, G.,Zinn-Justin, S. (deposition date: 2021-02-02, release date: 2021-04-07, Last modification date: 2024-11-13)

Primary citation

Marcelot, A.,Petitalot, A.,Ropars, V.,Le Du, M.H.,Samson, C.,Dubois, S.,Hoffmann, G.,Miron, S.,Cuniasse, P.,Marquez, J.A.,Thai, R.,Theillet, F.X.,Zinn-Justin, S.
Di-phosphorylated BAF shows altered structural dynamics and binding to DNA, but interacts with its nuclear envelope partners.
Nucleic Acids Res., 49:3841-3855, 2021

PubMed Abstract: Barrier-to-autointegration factor (BAF), encoded by the BANF1 gene, is an abundant and ubiquitously expressed metazoan protein that has multiple functions during the cell cycle. Through its ability to cross-bridge two double-stranded DNA (dsDNA), it favours chromosome compaction, participates in post-mitotic nuclear envelope reassembly and is essential for the repair of large nuclear ruptures. BAF forms a ternary complex with the nuclear envelope proteins lamin A/C and emerin, and its interaction with lamin A/C is defective in patients with recessive accelerated aging syndromes. Phosphorylation of BAF by the vaccinia-related kinase 1 (VRK1) is a key regulator of BAF localization and function. Here, we demonstrate that VRK1 successively phosphorylates BAF on Ser4 and Thr3. The crystal structures of BAF before and after phosphorylation are extremely similar. However, in solution, the extensive flexibility of the N-terminal helix α1 and loop α1α2 in BAF is strongly reduced in di-phosphorylated BAF, due to interactions between the phosphorylated residues and the positively charged C-terminal helix α6. These regions are involved in DNA and lamin A/C binding. Consistently, phosphorylation causes a 5000-fold loss of affinity for dsDNA. However, it does not impair binding to lamin A/C Igfold domain and emerin nucleoplasmic region, which leaves open the question of the regulation of these interactions.

PubMed: 33744941
DOI: 10.1093/nar/gkab184

Experimental method

X-RAY DIFFRACTION (1.44 Å)