DnaB and DciA: Mechanisms of Helicase Loading and Translocation on ssDNA.

Replicative helicases are assembled on chromosomes by helicase loaders before initiation of DNA replication. Here, we investigate mechanisms used by the bacterial DnaB replicative helicase and the DciA helicase loader. In the present structure of the DnaB-ssDNA•ATPγS complex, the amino-terminal (NTD) tier, previously found as an open spiral in a GDP•AlF4 complex, was observed to adopt a closed planar arrangement.

Implementation of a pooled surveillance testing program for asymptomatic SARS-CoV-2 infections in K-12 schools and universities.

Background: The negative impact of continued school closures during the height of the COVID-19 pandemic warrants the establishment of cost-effective strategies for surveillance and screening to safely reopen and monitor for potential in-school transmission. Here, we present a novel approach to increase the availability of repetitive and routine COVID-19 testing that may ultimately reduce the overall viral burden in the community.

Methods: We implemented a testing program using the SalivaClear࣪ pooled surveillance method that included students, faculty and staff from K-12 schools (student age range 5-18 years) and universities (student age range >18 years) across the country (Mirimus Clinical Labs, Brooklyn, NY).