Duplex Unwinding Mechanism of Coronavirus MERS-CoV nsp13 Helicase.

ABSTRACT: The COVID-19 pandemic has underscored the importance of in-depth research into the proteins encoded by coronaviruses (CoV), particularly the highly conserved nonstructural CoV proteins (nsp). Among these, the nsp13 helicase of severe pathogenic MERS-CoV, SARS-CoV-2, and SARS-CoV is one of the most preserved CoV nsp. Utilizing single-molecule FRET, we discovered that MERS-CoV nsp13 unwinds DNA in distinct steps of about 9 bp when ATP is employed. If a different nucleotide is introduced, these steps diminish to 3-4 bp. Dwell-time analysis revealed 3-4 concealed steps within each unwinding process, which suggests the hydrolysis of 3-4 dTTP. Combining our observations with previous studies, we propose an unwinding model of CoV nsp13 helicase. This model suggests that the elongated and adaptabl

SUBMITTER: Hao W 

PROVIDER: S-EPMC11863148 | biostudies-literature | 2025 Feb

REPOSITORIES: biostudies-literature