Portal de Periódicos da CAPES

Molecular basis for transposase activation by a dedicated AAA+ ATPase

2024; Nature Portfolio; Volume: 630; Issue: 8018 Linguagem: Inglês

10.1038/s41586-024-07550-6

1476-4687

Álvaro de la Gándara, Mercedes Spínola‐Amilibia, Lidia Araújo‐Bazán, Rafael Núñez‐Ramírez, James M. Berger, Ernesto Arias‐Palomo,

CRISPR and Genetic Engineering

Abstract Transposases drive chromosomal rearrangements and the dissemination of drug-resistance genes and toxins 1–3 . Although some transposases act alone, many rely on dedicated AAA+ ATPase subunits that regulate site selectivity and catalytic function through poorly understood mechanisms. Using IS 21 as a model transposase system, we show how an ATPase regulator uses nucleotide-controlled assembly and DNA deformation to enable structure-based site selectivity, transposase recruitment, and activation and integration. Solution and cryogenic electron microscopy studies show that the IstB ATPase self-assembles into an autoinhibited pentamer of dimers that tightly curves target DNA into a half-coil. Two of these decamers dimerize, which stabilizes the target nucleic acid into a kinked S-shaped configuration that engages the IstA transposase at the interface between the two IstB oligomers to form an approximately 1 MDa transpososome complex. Specific interactions stimulate regulator ATPase activity and trigger a large conformational change on the transposase that positions the catalytic site to perform DNA strand transfer. These studies help explain how AAA+ ATPase regulators—which are used by classical transposition systems such as Tn7, Mu and CRISPR-associated elements—can remodel their substrate DNA and cognate transposases to promote function.