title: Architecture of a full-length retroviral integrase monomer and dimer, revealed by small angle X-ray scattering and chemical cross-linking.
abstract: We determined the size and shape of full-length avian sarcoma virus (ASV) integrase (IN) monomers and dimers in solution using small angle x-ray scattering. The low resolution data obtained establish constraints for the relative arrangements of the three component domains in both forms. Domain organization within the small angle x-ray envelopes was determined by combining available atomic resolution data for individual domains with results from cross-linking coupled with mass spectrometry. The full-length dimer architecture so revealed is unequivocally different from that proposed from x-ray crystallographic analyses of two-domain fragments, in which interactions between the catalytic core domains play a prominent role. Core-core interactions are detected only in cross-linked IN tetramers and are required for concerted integration. The solution dimer is stabilized by C-terminal domain (CTD-CTD) interactions and by interactions of the N-terminal domain in one subunit with the core and CTD in the second subunit. These results suggest a pathway for formation of functional IN-DNA complexes that has not previously been considered and possible strategies for preventing such assembly.
authors: Institute for Cancer Research, Fox Chase Cancer Center, Philadelphia, Pennsylvania 19111, USA.
authors: Ravi S
authors: RS
authors: Bojja
authors: Mark D
authors: MD
authors: Andrake
authors: Steven
authors: S
authors: Weigand
authors: George
authors: G
authors: Merkel
authors: Olya
authors: O
authors: Yarychkivska
authors: Adam
authors: A
authors: Henderson
authors: Marissa
authors: M
authors: Kummerling
authors: Anna Marie
authors: AM
authors: Skalka
mesh_terms: D003432:Cross-Linking Reagents / Q000737:chemistry / Q000494:pharmacology; D004247:DNA / Q000737:chemistry; D030562:Databases, Protein; D019281:Dimerization; D019427:HIV Integrase / Q000737:chemistry; D019426:Integrases / Q000737:chemistry*; D008027:Light; D013058:Mass Spectrometry / Q000379:methods; D008968:Molecular Conformation; D011485:Protein Binding; D025941:Protein Interaction Mapping / Q000379:methods; D012190:Retroviridae / Q000201:enzymology*; D053838:Scattering, Small Angle; D014965:X-Rays
chemical_list: D003432:Cross-Linking Reagents; D004247:DNA; D019427:HIV Integrase; D019426:Integrases