4U7B: Crystal Structure Of A Pre-cleavage Mos1 Transpososome

During cut-and-paste mariner/Tc1 transposition, transposon DNA is cut precisely at its junction with flanking DNA, ensuring the transposon is neither shortened nor lengthened with each transposition event. Each transposon end is flanked by a TpA dinucleotide: the signature target site duplication of mariner/Tc1 transposition. To establish the role of this sequence in accurate DNA cleavage, we have determined the crystal structure of a pre-second strand cleavage mariner Mos1 transpososome. The structure reveals the route of an intact DNA strand through the transposase active site before second strand cleavage. The crossed architecture of this pre-second strand cleavage paired-end complex supports our proposal that second strand cleavage occurs in trans. The conserved mariner transposase WVPHEL and YSPDL motifs position the strand for accurate DNA cleavage. Base-specific recognition of the flanking DNA by conserved amino acids is revealed, defining a new role for the WVPHEL motif in mariner transposition and providing a molecular explanation for in vitro mutagenesis data. Comparison of the pre-TS cleavage and post-cleavage Mos1 transpososomes with structures of Prototype Foamy Virus intasomes suggests a binding mode for target DNA prior to Mos1 transposon integration.
PDB ID: 4U7BDownload
MMDB ID: 126905
PDB Deposition Date: 2014/7/30
Updated in MMDB: 2015/03
Experimental Method:
x-ray diffraction
Resolution: 3.09  Å
Source Organism:
Similar Structures:
Biological Unit for 4U7B: hexameric; determined by author and by software (PISA)
Molecular Components in 4U7B
Label Count Molecule
Proteins (2 molecules)
Mariner Mos1 Transposase
Molecule annotation
Nucleotides(2 molecules)
DNA (25-mer)
Molecule annotation
DNA (31-mer)
Molecule annotation
Chemicals (3 molecules)
* Click molecule labels to explore molecular sequence information.

Citing MMDB