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IS21 family transposase cleaved donor complex traps two right-handed superhelical crossings.

Mercedes Spínola-AmilibiaLidia Araújo-BazánÁlvaro de la GándaraJames M BergerErnesto Arias-Palomo
Published in: Nature communications (2023)
Transposases are ubiquitous enzymes that catalyze DNA rearrangement events with broad impacts on gene expression, genome evolution, and the spread of drug-resistance in bacteria. Here, we use biochemical and structural approaches to define the molecular determinants by which IstA, a transposase present in the widespread IS21 family of mobile elements, catalyzes efficient DNA transposition. Solution studies show that IstA engages the transposon terminal sequences to form a high-molecular weight complex and promote DNA integration. A 3.4 Å resolution structure of the transposase bound to transposon ends corroborates our biochemical findings and reveals that IstA self-assembles into a highly intertwined tetramer that synapses two supercoiled terminal inverted repeats. The three-dimensional organization of the IstA•DNA cleaved donor complex reveals remarkable similarities with retroviral integrases and classic transposase systems, such as Tn7 and bacteriophage Mu, and provides insights into IS21 transposition.
Keyphrases
  • single molecule
  • circulating tumor
  • cell free
  • gene expression
  • nucleic acid
  • dna methylation
  • circulating tumor cells
  • genome wide