3HPH TRANSFERASE, PROTEIN-PROTEIN COMPLEX, TETRAMER, DNA INTEGRATION, ENDONUCLEASE, MAGNESIUM, METAL-BINDING, MULTIFUNCTIONAL ENZYME, NUCLEASE, NUCLEOTIDYLTRANSFERASE, NUCLEUS, VIRAL NUCLEOPROTEIN, VIRION, ZINC, DNA- BINDING, HOST-VIRUS INTERACTION, TRANSCRIPTION, TRANSCRIPTION REGULATION, ZINC BINDING, HHCC MOTIF, VIRAL PROTEIN, RECOMBINATION CLOSED TETRAMER OF VISNA VIRUS INTEGRASE (RESIDUES 1-219) IN COMPLEX WITH LEDGF IBD