The SMC-family Wadjet complex protects bacteria from plasmid transformation by recognition and cleavage of closed-circular DNA.

ABSTRACT: Self versus non-self discrimination is a key element of innate and adaptive immunity across life. In bacteria, CRISPR-Cas and restriction-modification systems recognize non-self nucleic acids through their sequence and their methylation state, respectively. Here, we show that the Wadjet defense system recognizes DNA topology to protect its host against plasmid transformation. By combining cryoelectron microscopy with cross-linking mass spectrometry, we show that Wadjet forms a complex similar to the bacterial condensin complex MukBEF, with a novel nuclease subunit similar to a type II DNA topoisomerase. Wadjet specifically cleaves closed-circular DNA in a reaction requiring ATP hydrolysis by the structural maintenance of chromosome (SMC) ATPase subunit JetC, suggesting that the complex cou

SUBMITTER: Deep A 

PROVIDER: S-EPMC9637719 | biostudies-literature | 2022 Nov

REPOSITORIES: biostudies-literature