Molecular basis of C-S bond cleavage in the glycyl radical enzyme isethionate sulfite-lyase
Name
1-s2.0-S2451945621001100-main.pdf
Description
Published version
Size
4.32 MB
Format
Adobe PDF
Checksum (MD5)
686785c5efdcc01f44faf860506b13dc
Author(s)
Dawson, Christopher D
Irwin, Stephania M
Backman, Lindsey RF
Le, Chip
Wang, Jennifer X
Vennelakanti, Vyshnavi
Yang, Zhongyue
Kulik, Heather J
Drennan, Catherine L
Balskus, Emily P
Date Issued
2021
Journal
Cell Chemical Biology
Publisher
Elsevier BV
Version
Final published version
Abstract
Desulfonation of isethionate by the bacterial glycyl radical enzyme (GRE) isethionate sulfite-lyase (IslA) generates sulfite, a substrate for respiration that in turn produces the disease-associated metabolite hydrogen sulfide. Here, we present a 2.7 Å resolution X-ray structure of wild-type IslA from Bilophila wadsworthia with isethionate bound. In comparison with other GREs, alternate positioning of the active site β strands allows for distinct residue positions to contribute to substrate binding. These structural differences, combined with sequence variations, create a highly tailored active site for the binding of the negatively charged isethionate substrate. Through the kinetic analysis of 14 IslA variants and computational analyses, we probe the mechanism by which radical chemistry is used for C-S bond cleavage. This work further elucidates the structural basis of chemistry within the GRE superfamily and will inform structure-based inhibitor design of IsIA and thus of microbial hydrogen sulfide production.
MIT Department
Massachusetts Institute of Technology. Department of Biology
Massachusetts Institute of Technology. Department of Chemistry
Massachusetts Institute of Technology. Department of Chemical Engineering
Howard Hughes Medical Institute
Terms of Use
Creative Commons Attribution 4.0 International license
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DOI of Published Version
https://doi.org/10.1016/j.chembiol.2021.03.001
