title: Role of the 207-218 peptide region of Moloney murine leukemia virus integrase in enzyme catalysis.
abstract: X-ray diffraction data on a few retroviral integrases show a flexible loop near the active site. By sequence alignment, the peptide region 207-218 of Mo-MLV IN appears to correspond to this flexible loop. In this study, residues H208, Y211, R212, Q214, S215 and S216 of Mo-MLV IN were mutated to determine their role on enzyme activity. We found that Y211A, R212A, R212K and Q214A decreased integration activity, while disintegration and 3'-processing were not significantly affected. By contrast H208A was completely inactive in all the assays. The core domain of Mo-MLV integrase was modeled and the flexibility of the region 207-216 was analyzed. Substitutions with low integration activity showed a lower flexibility than wild type integrase. We propose that the peptide region 207-216 is a flexible loop and that H208, Y211, R212 and Q214 of this loop are involved in the correct assembly of the DNA-integrase complex during integration.
authors.affiliation: Programa de Virología, Instituto de Ciencias Biomédicas, Facultad de Medicina, Universidad de Chile, Independencia 1027, Santiago, Chile. macevedo@med.uchile.cl
authors.forename: Mónica L
authors.initials: ML
authors.lastname: Acevedo
authors.forename: José Jaime
authors.initials: JJ
authors.lastname: Arbildúa
authors.forename: Octavio
authors.initials: O
authors.lastname: Monasterio
authors.forename: Héctor
authors.initials: H
authors.lastname: Toledo
authors.forename: Oscar
authors.initials: O
authors.lastname: León
mesh_terms: D000595:Amino Acid Sequence; D019426:Integrases / Q000737:chemistry / Q000235:genetics* / Q000378:metabolism*; D008958:Models, Molecular; D008979:Moloney murine leukemia virus / Q000201:enzymology* / Q000235:genetics; D016297:Mutagenesis, Site-Directed; D009154:Mutation; D017434:Protein Structure, Tertiary; D016415:Sequence Alignment; D016662:Virus Integration
chemical_list: D019426:Integrases