Structural and functional basis of low-affinity SAM/SAH-binding in the conserved MTase of the multi-segmented Alongshan virus distantly related to canonical unsegmented flaviviruses.

Bibliographic Details
Title: Structural and functional basis of low-affinity SAM/SAH-binding in the conserved MTase of the multi-segmented Alongshan virus distantly related to canonical unsegmented flaviviruses.
Authors: Hua Chen, Sheng Lin, Fanli Yang, Zimin Chen, Liyan Guo, Jing Yang, Xi Lin, Lingling Wang, Yanping Duan, Ao Wen, Xindan Zhang, Yushan Dai, Keqing Yin, Xin Yuan, Chongzhang Yu, Yarong He, Bin He, Yu Cao, Haohao Dong, Jian Li, Qi Zhao, Quan Liu, Guangwen Lu
Source: PLoS Pathogens, Vol 19, Iss 10, p e1011694 (2023)
Publisher Information: Public Library of Science (PLoS), 2023.
Publication Year: 2023
Collection: LCC:Immunologic diseases. Allergy
LCC:Biology (General)
Subject Terms: Immunologic diseases. Allergy, RC581-607, Biology (General), QH301-705.5
More Details: Alongshan virus (ALSV), a newly discovered member of unclassified Flaviviridae family, is able to infect humans. ALSV has a multi-segmented genome organization and is evolutionarily distant from canonical mono-segmented flaviviruses. The virus-encoded methyltransferase (MTase) plays an important role in viral replication. Here we show that ALSV MTase readily binds S-adenosyl-L-methionine (SAM) and S-adenosyl-L-homocysteine (SAH) but exhibits significantly lower affinities than canonical flaviviral MTases. Structures of ALSV MTase in the free and SAM/SAH-bound forms reveal that the viral enzyme possesses a unique loop-element lining side-wall of the SAM/SAH-binding pocket. While the equivalent loop in flaviviral MTases half-covers SAM/SAH, contributing multiple hydrogen-bond interactions; the pocket-lining loop of ALSV MTase is of short-length and high-flexibility, devoid of any physical contacts with SAM/SAH. Subsequent mutagenesis data further corroborate such structural difference affecting SAM/SAH-binding. Finally, we also report the structure of ALSV MTase bound with sinefungin, an SAM-analogue MTase inhibitor. These data have delineated the basis for the low-affinity interaction between ALSV MTase and SAM/SAH and should inform on antiviral drug design.
Document Type: article
File Description: electronic resource
Language: English
ISSN: 1553-7366
1553-7374
Relation: https://journals.plos.org/plospathogens/article/file?id=10.1371/journal.ppat.1011694&type=printable; https://doaj.org/toc/1553-7366; https://doaj.org/toc/1553-7374
DOI: 10.1371/journal.ppat.1011694&type=printable
DOI: 10.1371/journal.ppat.1011694
Access URL: https://doaj.org/article/9a374ab188f74bdbbce0d0cf34472fe8
Accession Number: edsdoj.9a374ab188f74bdbbce0d0cf34472fe8
Database: Directory of Open Access Journals
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More Details
ISSN:15537366
15537374
DOI:10.1371/journal.ppat.1011694&type=printable
Published in:PLoS Pathogens
Language:English