Download MendeleyStructural insights from active site variants and beta-8 loop interactions in viperin-like enzymes.
Lachowicz, J.C., Grudman, S., Bonanno, J.B., Fiser, A., Grove, T.L.(2025) Structure
- PubMed: 40373765
- DOI: https://doi.org/10.1016/j.str.2025.04.009
- Primary Citation of Related Structures:
9DFN, 9DFU, 9DFW, 9DGW - PubMed Abstract:
Viperin and viperin-like enzymes (VLEs) are members of the radical SAM superfamily that perform radical-mediated dehydrations on nucleoside triphosphates to yield 3'-deoxy-3',4'-didehydronucleoside triphosphates (ddhNTPs). Interestingly, viperin and VLEs demonstrate species-dependent substrate selectivity. Some fungal species have a second VLE and, while most viperin and VLEs contain an NΦHX 4 CX 3 CX 2 CF motif, these secondary VLEs are catalytically hindered by a histidine to phenylalanine substitution, an NΦFX 4 CX 3 CX 2 CF motif (NΦF). Herein, we utilize a combination of bioinformatics, enzymology, and X-ray crystallography to demonstrate that NΦF VLEs likely utilize CTP as a substrate. Based on these observations, we demonstrate that the β-8 loop in TvVip1 can be engineered with the β-8 loop from a CTP-selective viperin (Mus musculus) to "swap" substrate selectivity from UTP to CTP. These results provide insight into the determinants of substrate selectivity exhibited by VLEs and introduce a potential route for engineering viperin and VLEs to form alternative ddhNTPs.
Organizational Affiliation:
Department of Biochemistry, Albert Einstein College of Medicine, Bronx, NY 10461, USA.
