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.
Guanosine triphosphate acts as a cofactor to promote assembly of initial P-element transposase-DNA synaptic complexes / Tang, M; Cecconi, Ciro; Kim, H; Bustamante, C; Rio, Dc. - In: GENES & DEVELOPMENT. - ISSN 0890-9369. - 19:(2005), pp. 1422-1425. [10.1101/gad.1317605]