Characterization and Mechanistic Study of the Radical SAM Enzyme ArsS Involved in Arsenosugar Biosynthesis.
Angew Chem Int Ed Engl
; 60(14): 7570-7575, 2021 03 29.
Article
en En
| MEDLINE
| ID: mdl-33427387
ABSTRACT
Arsenosugars are a group of arsenic-containing ribosides that are found predominantly in marine algae but also in terrestrial organisms. It has been proposed that arsenosugar biosynthesis involves a key intermediate 5'-deoxy-5'-dimethylarsinoyl-adenosine (DDMAA), but how DDMAA is produced remains elusive. Now, we report characterization of ArsS as a DDMAA synthase, which catalyzes a radical S-adenosylmethionine (SAM)-mediated alkylation (adenosylation) of dimethylarsenite (DMAsIII ) to produce DDMAA. This radical-mediated reaction is redox neutral, and multiple turnover can be achieved without external reductant. Phylogenomic and biochemical analyses revealed that DDMAA synthases are widespread in distinct bacterial phyla with similar catalytic efficiencies; these enzymes likely originated from cyanobacteria. This study reveals a key step in arsenosugar biosynthesis and also a new paradigm in radical SAM chemistry, highlighting the catalytic diversity of this superfamily of enzymes.
Palabras clave
Texto completo:
1
Colección:
01-internacional
Banco de datos:
MEDLINE
Asunto principal:
S-Adenosilmetionina
/
Adenosina
/
Monosacáridos
Idioma:
En
Revista:
Angew Chem Int Ed Engl
Año:
2021
Tipo del documento:
Article
País de afiliación:
China