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-Structure paper
Title | Multivalent interactions essential for lentiviral integrase function. |
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Journal, issue, pages | Nat Commun, Vol. 13, Issue 1, Page 2416, Year 2022 |
Publish date | May 3, 2022 |
Authors | Allison Ballandras-Colas / Vidya Chivukula / Dominika T Gruszka / Zelin Shan / Parmit K Singh / Valerie E Pye / Rebecca K McLean / Gregory J Bedwell / Wen Li / Andrea Nans / Nicola J Cook / Hind J Fadel / Eric M Poeschla / David J Griffiths / Javier Vargas / Ian A Taylor / Dmitry Lyumkis / Hasan Yardimci / Alan N Engelman / Peter Cherepanov / |
PubMed Abstract | A multimer of retroviral integrase (IN) synapses viral DNA ends within a stable intasome nucleoprotein complex for integration into a host cell genome. Reconstitution of the intasome from the maedi- ...A multimer of retroviral integrase (IN) synapses viral DNA ends within a stable intasome nucleoprotein complex for integration into a host cell genome. Reconstitution of the intasome from the maedi-visna virus (MVV), an ovine lentivirus, revealed a large assembly containing sixteen IN subunits. Herein, we report cryo-EM structures of the lentiviral intasome prior to engagement of target DNA and following strand transfer, refined at 3.4 and 3.5 Å resolution, respectively. The structures elucidate details of the protein-protein and protein-DNA interfaces involved in lentiviral intasome formation. We show that the homomeric interfaces involved in IN hexadecamer formation and the α-helical configuration of the linker connecting the C-terminal and catalytic core domains are critical for MVV IN strand transfer activity in vitro and for virus infectivity. Single-molecule microscopy in conjunction with photobleaching reveals that the MVV intasome can bind a variable number, up to sixteen molecules, of the lentivirus-specific host factor LEDGF/p75. Concordantly, ablation of endogenous LEDGF/p75 results in gross redistribution of MVV integration sites in human and ovine cells. Our data confirm the importance of the expanded architecture observed in cryo-EM studies of lentiviral intasomes and suggest that this organization underlies multivalent interactions with chromatin for integration targeting to active genes. |
External links | Nat Commun / PubMed:35504909 / PubMed Central |
Methods | EM (single particle) |
Resolution | 3.46 Å |
Structure data | EMDB-26322, PDB-7u32: |
Chemicals | ChemComp-ZN: ChemComp-CA: |
Source |
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Keywords | VIRAL PROTEIN/DNA / Integrase-DNA complex / hydrolase / VIRAL PROTEIN / VIRAL PROTEIN-DNA complex |