Unlabelled: Methanethiol (MT) is a sulfur-containing compound produced during dimethylsulfoniopropionate (DMSP) degradation by marine bacteria. The C-S bond of MT can be cleaved by methanethiol oxidases (MTOs) to release a sulfur atom. However, the cleaving process remains unclear, and the species of sulfur product is uncertain. It has long been assumed that MTOs produce hydrogen sulfide (HS) from MT. Herein, we studied the MTOs in the Rhodobacteraceae family-whose members are important DMSP degraders ubiquitous in marine environments. We identified 57 MTOs from 1,904 Rhodobacteraceae genomes. These MTOs were grouped into two major clusters. Cluster 1 members share three conserved cysteine residues, while cluster 2 members contain one conserved cysteine residue. We examined the products of three representative MTOs both and . All of them produced sulfane sulfur other than HS from MT. Their conserved cysteines are substrate-binding sites in which the MTO-S-S-CH complex is formed. This finding clarified the sulfur product of MTOs and enlightened the MTO-catalyzing process. Moreover, this study connected DMSP degradation with sulfane sulfur metabolism, filling a critical gap in the DMSP degradation pathway and representing new knowledge in the marine sulfur cycle field.
Importance: This study overthrows a long-time assumption that methanethiol oxidases (MTOs) cleave the C-S bond of methanethiol to produce both HS and HO-the former is a strong reductant and the latter is a strong oxidant. From a chemistry viewpoint, this reaction is difficult to happen. Investigations on three representative MTOs indicated that sulfane sulfur (S) was the direct product, and no HO was produced. Finally, the products of MTOs were corrected to be S and HO. This finding connected dimethylsulfoniopropionate (DMSP) degradation with sulfane sulfur metabolism, filling a critical gap in the DMSP degradation pathway and representing new knowledge in the marine sulfur cycle field.
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http://dx.doi.org/10.1128/mbio.02907-23 | DOI Listing |
Pharmacol Res
January 2025
Clinical, Experimental Surgery and Translational Research Center, Biomedical Research Foundation Academy of Athens, Greece; Faculty of Pharmacy, National and Kapodistrian University of Athens, Greece. Electronic address:
Metabolic syndrome (MetS) is a cluster of metabolic abnormalities that occur concurrently and increase the risk of cardiovascular disease. 3-mercaptopyruvate sulfurtransferase (MPST) is a cysteine-catabolizing enzyme that yields pyruvate and hydrogen sulfide (HS) and plays a central role in the regulation of energy homeostasis. Herein, we seek to investigate the role of MPST/HS in MetS and its cardiovascular consequences using a mouse model of the disease.
View Article and Find Full Text PDFRedox Biol
December 2024
Department of Analytical Biochemistry, Meiji Pharmaceutical University, 2-522-1 Noshio, Kiyose, Tokyo, 204-8588, Japan. Electronic address:
Unfolded protein response (UPR) is activated in cells under endoplasmic reticulum (ER) stress. One sensor protein involved in this response is PERK, which is activated through its redox-dependent oligomerization. Prolonged UPR activation is associated with the development and progression of various diseases, making it essential to understanding the redox regulation of PERK.
View Article and Find Full Text PDFInt J Mol Sci
October 2024
Department of Biochemistry and Cell Physiology, Voronezh State University, 394018 Voronezh, Russia.
Representatives of the colorless sulfur bacteria of the genus use reduced sulfur compounds in the processes of lithotrophic growth, which is accompanied by the storage of intracellular sulfur. However, it is still unknown how the transformation of intracellular sulfur occurs in representatives. Annotation of the genome of D-402 did not identify any genes for the oxidation or reduction of elemental sulfur.
View Article and Find Full Text PDFInorg Chem
October 2024
Department of Biochemistry and Molecular Biology, Graduate School of Science and Engineering, Saitama University, Saitama 338-8570, Japan.
SufU, a component of the SufCDSUB Fe-S cluster biosynthetic system, serves as a Zn-dependent sulfur-carrying protein that delivers inorganic sulfur in the form of cysteine persulfide from SufS to SufBCD. To understand this sulfur delivery mechanism, we studied the X-ray crystal structure of SufU and its sulfur-carrying state (persulfurated SufU) and performed functional analysis of the conserved amino acid residues around the Zn sites. Interestingly, sulfur-carrying SufU with Cys41-persulfide (Cys41-S-S) exhibited a unique Zn coordination structure, in which electrophilic S is ligated to Zn and nucleophilic/anionic S is bound to distally conserved Arg125.
View Article and Find Full Text PDFBiol Chem
September 2024
INRES-Chemical Signalling, University of Bonn, Friedrich-Ebert-Allee 144, D-53113 Bonn, Germany.
Posttranslational modifications (PTMs) can modulate the activity, localization and interactions of proteins and (re)define their biological function. Understanding how changing environments can alter cellular processes thus requires detailed knowledge about the dynamics of PTMs in time and space. A PTM that gained increasing attention in the last decades is protein persulfidation, where a cysteine thiol (-SH) is covalently bound to sulfane sulfur to form a persulfide (-SSH).
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