Structural and biochemical characterization of an encapsulin-associated rhodanese from Acinetobacter baumannii.
Protein Sci
; 33(8): e5129, 2024 Aug.
Article
em En
| MEDLINE
| ID: mdl-39073218
ABSTRACT
Rhodanese-like domains (RLDs) represent a widespread protein family canonically involved in sulfur transfer reactions between diverse donor and acceptor molecules. RLDs mediate these transsulfuration reactions via a transient persulfide intermediate, created by modifying a conserved cysteine residue in their active sites. RLDs are involved in various aspects of sulfur metabolism, including sulfide oxidation in mitochondria, iron-sulfur cluster biogenesis, and thio-cofactor biosynthesis. However, due to the inherent complexity of sulfur metabolism caused by the intrinsically high nucleophilicity and redox sensitivity of thiol-containing compounds, the physiological functions of many RLDs remain to be explored. Here, we focus on a single domain Acinetobacter baumannii RLD (Ab-RLD) associated with a desulfurase encapsulin which is able to store substantial amounts of sulfur inside its protein shell. We determine the 1.6 Å x-ray crystal structure of Ab-RLD, highlighting a homodimeric structure with a number of unusual features. We show through kinetic analysis that Ab-RLD exhibits thiosulfate sulfurtransferase activity with both cyanide and glutathione acceptors. Using native mass spectrometry and in vitro assays, we provide evidence that Ab-RLD can stably carry a persulfide and thiosulfate modification and may employ a ternary catalytic mechanism. Our results will inform future studies aimed at investigating the functional link between Ab-RLD and the desulfurase encapsulin.
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Texto completo:
1
Coleções:
01-internacional
Base de dados:
MEDLINE
Assunto principal:
Tiossulfato Sulfurtransferase
/
Proteínas de Bactérias
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Acinetobacter baumannii
Idioma:
En
Revista:
Protein Sci
Ano de publicação:
2024
Tipo de documento:
Article