5bq5

Publication Abstract from PubMed

Transposons are ubiquitous genetic elements that drive genome rearrangements, evolution, and the spread of infectious disease and drug-resistance. Many transposons, such as Mu, Tn7, and IS21, require regulatory AAA+ ATPases for function. We use X-ray crystallography and cryo-electron microscopy to show that the ATPase subunit of IS21, IstB, assembles into a clamshell-shaped decamer that sandwiches DNA between two helical pentamers of ATP-associated AAA+ domains, sharply bending the duplex into a 180 degrees U-turn. Biochemical studies corroborate key features of the structure and further show that the IS21 transposase, IstA, recognizes the IstB*DNA complex and promotes its disassembly by stimulating ATP hydrolysis. Collectively, these studies reveal a distinct manner of higher-order assembly and client engagement by a AAA+ ATPase and suggest a mechanistic model where IstB binding and subsequent DNA bending primes a selected insertion site for efficient transposition.

An Atypical AAA+ ATPase Assembly Controls Efficient Transposition through DNA Remodeling and Transposase Recruitment.,Arias-Palomo E, Berger JM Cell. 2015 Aug 13;162(4):860-71. doi: 10.1016/j.cell.2015.07.037. PMID:26276634^[1]

From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine.