Richardson, J.M., Dawson, A., O'Hagan, N., Taylor, P., Finnegan, D.J., Walkinshaw, M.D. (2006). Mechanism of Mos1 transposition: insights from structural analysis.  EMBO J. 25(6): 1324--1334.

FBrf0190366

Research paper

We present the crystal structure of the catalytic domain of Mos1 transposase, a member of the Tc1/mariner family of transposases. The structure comprises an RNase H-like core, bringing together an aspartic acid triad to form the active site, capped by N- and C-terminal alpha-helices. We have solved structures with either one Mg2+ or two Mn2+ ions in the active site, consistent with a two-metal mechanism for catalysis. The lack of hairpin-stabilizing structural motifs is consistent with the absence of a hairpin intermediate in Mos1 excision. We have built a model for the DNA-binding domain of Mos1 transposase, based on the structure of the bipartite DNA-binding domain of Tc3 transposase. Combining this with the crystal structure of the catalytic domain provides a model for the paired-end complex formed between a dimer of Mos1 transposase and inverted repeat DNA. The implications for the mechanisms of first and second strand cleavage are discussed.

PMC1422158 (PMC) (EuropePMC)