tetano
Editor, Senior Moderator
Chem Biomed Imaging
. 2024 Dec 19;3(2):111-122.
doi: 10.1021/cbmi.4c00077. eCollection 2025 Feb 24. Duplex Unwinding Mechanism of Coronavirus MERS-CoV nsp13 Helicase
Wei Hao[SUP] 1 [/SUP], Xiao Hu[SUP] 2 [/SUP], Qixin Chen[SUP] 2 [/SUP], Bo Qin[SUP] 1 [/SUP], Zhiqi Tian[SUP] 2 [/SUP], Ziheng Li[SUP] 1 [/SUP], Pengjiao Hou[SUP] 1 [/SUP], Rong Zhao[SUP] 1 [/SUP], Hamza Balci[SUP] 3 [/SUP], Sheng Cui[SUP] 1 [/SUP], Jiajie Diao[SUP] 2 [/SUP]
Affiliations
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 adaptable 1B-stalk of nsp13 may enable the 1B remnants to engage with the unwound single-stranded DNA, even as the helicase core domain has advanced over 3-4 bp, thereby inducing accumulated strain on the nsp13-DNA complex. Our findings provide a foundational framework for determining the unwinding mechanism of this unique helicase family.
. 2024 Dec 19;3(2):111-122.
doi: 10.1021/cbmi.4c00077. eCollection 2025 Feb 24. Duplex Unwinding Mechanism of Coronavirus MERS-CoV nsp13 Helicase
Wei Hao[SUP] 1 [/SUP], Xiao Hu[SUP] 2 [/SUP], Qixin Chen[SUP] 2 [/SUP], Bo Qin[SUP] 1 [/SUP], Zhiqi Tian[SUP] 2 [/SUP], Ziheng Li[SUP] 1 [/SUP], Pengjiao Hou[SUP] 1 [/SUP], Rong Zhao[SUP] 1 [/SUP], Hamza Balci[SUP] 3 [/SUP], Sheng Cui[SUP] 1 [/SUP], Jiajie Diao[SUP] 2 [/SUP]
Affiliations
- PMID: 40018651
- PMCID: PMC11863148
- DOI: 10.1021/cbmi.4c00077
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 adaptable 1B-stalk of nsp13 may enable the 1B remnants to engage with the unwound single-stranded DNA, even as the helicase core domain has advanced over 3-4 bp, thereby inducing accumulated strain on the nsp13-DNA complex. Our findings provide a foundational framework for determining the unwinding mechanism of this unique helicase family.