*5.8. Statistical Analysis*

All the statistical analyses were performed using GraphPad software, version 9.0.0 (San Diego, CA, USA). The statistical significance of the data was determined using Student's *t*-test (unpaired).

**Supplementary Materials:** The following supporting information can be downloaded online. Figure S1: MALDI TOF analysis of purified HEV-MTase. The major peak corresponds to the molecular weight of the HEV-MTase i.e., 37.07 kDa.

**Author Contributions:** Conceptualisation by P.H., M.I. and D.S.; methodology by P.H., M.I., P.B., S.S., D.M., M.M. and S.A.; Biophysical validation and software by R.K., N.A. and M.A.R.; validation by M.I., P.H. and K.K.I.; formal analysis by P.H., M.I. and D.S.; data curation by P.H. and M.I.; writing original and draft preparation by P.H. and M.I.; review and editing by M.I., A.T., N.A., A.F.A. and M.A.R.; supervision by D.S. and K.K.I.; funding acquisition by D.S. All authors have read and agreed to the published version of the manuscript.

**Funding:** Research work was funded by the Department of Biotechnology (DBT), India Sanction Order No., BT/PR15094/BRB/10/1446/2015 and Researchers Supporting Project number-RSP-2021/335, King Saud University, Riyadh, Saudi Arabia.

**Institutional Review Board Statement:** Not applicable.

**Informed Consent Statement:** Not applicable.

**Data Availability Statement:** Data is available within the article and supplementary file.

**Acknowledgments:** P.H. is thankful to Shiv Nadar University for financial support in the form of SRF. M.I. is thankful to the Department of Science and Technology (DST), New Delhi, India, for financial aid as Research Associate under project No. E.M.R./2015/001072. Authors are thankful to the Researchers Supporting Project number-RSP-2021/335, King Saud University, Riyadh, Saudi Arabia. The authors are also grateful to the Department of Biophysics, AIIMS, New Delhi and the Department of Chemistry, Shiv Nadar University, Greater Noida, India, for providing the instrumentational facility. The authors thank S.U. Emerson for providing the pSK-HEV-2, cDNA clone of HEV-Genotype 1.

**Conflicts of Interest:** The authors declare no conflict of interest.

**Sample Availability:** Samples of the compounds and MTase are available from the Deepak Sehgal's laboratory for the current research work.
