Three-dimensional structure of the Tn5 synaptic complex transposition intermediate.
Genomic evolution has been profoundly influenced by DNA transposition, a process whereby defined DNA segments move freely about the genome. Transposition is mediated by transposases, and similar events are catalyzed by retroviral integrases such as human immunodeficiency virus-1 (HIV-1) integrase. Understanding how these proteins interact with DNA is central to understanding the molecular basis of transposition. We report the three-dimensional structure of prokaryotic Tn5 transposase complexed with Tn5 transposon end DNA determined to 2.3 angstrom resolution. The molecular assembly is dimeric, where each double-stranded DNA molecule is bound by both protein subunits, orienting the transposon ends into the active sites. This structure provides a molecular framework for understanding many aspects of transposition, including the binding of transposon end DNA by one subunit and cleavage by a second, cleavage of two strands of DNA by a single active site via a hairpin intermediate, and strand transfer into target DNA.
Davies
D R
DR
Department of Biochemistry, University of Wisconsin, Madison, WI 53706, USA.
Goryshin
I Y
IY
Reznikoff
W S
WS
Rayment
I
I
D020816:Amino Acid Motifs; D001665:Binding Sites; D002384:Catalysis; D020134:Catalytic Domain; D003460:Crystallization; D018360:Crystallography, X-Ray; D004247:DNA / Q000737:chemistry* / Q000378:metabolism*; D004251:DNA Transposable Elements; D019281:Dimerization; D008345:Manganese / Q000378:metabolism; D009154:Mutation; D009690:Nucleic Acid Conformation; D010957:Plasmids; D011485:Protein Binding; D011487:Protein Conformation; D017510:Protein Folding; D017433:Protein Structure, Secondary; D017434:Protein Structure, Tertiary; D019895:Transposases / Q000737:chemistry* / Q000235:genetics / Q000378:metabolism*
D004251:DNA Transposable Elements; D008345:Manganese; D004247:DNA; D019895:Transposases