title: Guanosine triphosphate acts as a cofactor to promote assembly of initial P-element transposase-DNA synaptic complexes.
abstract: P transposable elements in Drosophila are members of a larger class of mobile elements that move using a cut-and-paste mechanism. P-element transposase uses guanosine triphosphate (GTP) as a cofactor for transposition. Here, we use atomic force microscopy (AFM) to visualize protein-DNA complexes formed during the initial stages of P-element transposition. These studies reveal that GTP acts to promote assembly of the first detectable noncovalent precleavage synaptic complex. This initial complex then randomly and independently cleaves each P-element end. These data show that GTP acts to promote protein-DNA assembly, and may explain why P-element excision often leads to unidirectional deletions.
authors.affiliation: Division of Genetics, Genomics and Development, Department of Molecular and Cell Biology, Center for Integrative Genomics, University of California, Berkeley, California 94720, USA.
authors.forename: Mei
authors.initials: M
authors.lastname: Tang
authors.forename: Ciro
authors.initials: C
authors.lastname: Cecconi
authors.forename: Helen
authors.initials: H
authors.lastname: Kim
authors.forename: Carlos
authors.initials: C
authors.lastname: Bustamante
authors.forename: Donald C
authors.initials: DC
authors.lastname: Rio
mesh_terms: D000818:Animals; D004247:DNA / Q000737:chemistry / Q000378:metabolism; D004251:DNA Transposable Elements / Q000502:physiology*; D004330:Drosophila / Q000378:metabolism; D006160:Guanosine Triphosphate / Q000378:metabolism*; D046911:Macromolecular Substances; D018625:Microscopy, Atomic Force; D019895:Transposases / Q000737:chemistry / Q000378:metabolism*
chemical_list: D004251:DNA Transposable Elements; D046911:Macromolecular Substances; D006160:Guanosine Triphosphate; D004247:DNA; D019895:Transposases