Discovery of a Biotin Synthase That Utilizes an Auxiliary 4Fe-5S Cluster for Sulfur Insertion

Biotin synthase (BioB) is a member of the Radical SAM superfamily of enzymes that catalyzes the terminal step of biotin (vitamin B7) biosynthesis, in which it inserts a sulfur atom in desthiobiotin to form a thiolane ring. How BioB accomplishes this difficult reaction has been the subject of much controversy, mainly around the source of the sulfur atom. However, it is now widely accepted that the sulfur atom inserted to form biotin stems from the sacrifice of the auxiliary 2Fe-2S cluster of BioB. Here, we bioinformatically explore the diversity of BioBs available in sequence databases and find an unexpected variation in the coordination of the auxiliary iron-sulfur cluster. After in vitro characterization, including the determination of biotin formation and representative crystal structures, we report a new type of BioB utilized by virtually all obligate anaerobic organisms. Instead of a 2Fe-2S cluster, this novel type of BioB utilizes an auxiliary 4Fe-5S cluster. Interestingly, this auxiliary 4Fe-5S cluster contains a ligated sulfide that we propose is used for biotin formation. We have termed this novel type of BioB, Type II BioB, with the E. coli 2Fe-2S cluster sacrificial BioB representing Type I. This surprisingly ubiquitous Type II BioB has implications for our understanding of the function and evolution of Fe-S clusters in enzyme catalysis, highlighting the difference in strategies between the anaerobic and aerobic world.

Medienart:

E-Artikel

Erscheinungsjahr:

2024

Erschienen:

2024

Enthalten in:

Zur Gesamtaufnahme - volume:146

Enthalten in:

Journal of the American Chemical Society - 146(2024), 3 vom: 24. Jan., Seite 1860-1873

Sprache:

Englisch

Beteiligte Personen:

Lachowicz, Jake C [VerfasserIn]
Lennox-Hvenekilde, David [VerfasserIn]
Myling-Petersen, Nils [VerfasserIn]
Salomonsen, Bo [VerfasserIn]
Verkleij, Gijs [VerfasserIn]
Acevedo-Rocha, Carlos G [VerfasserIn]
Caddell, Ben [VerfasserIn]
Gronenberg, Luisa S [VerfasserIn]
Almo, Steven C [VerfasserIn]
Sommer, Morten O A [VerfasserIn]
Genee, Hans J [VerfasserIn]
Grove, Tyler L [VerfasserIn]

Links:

Volltext

Themen:

6SO6U10H04
70FD1KFU70
Biotin
Biotin synthetase
EC 2.8.1.-
EC 2.8.1.6
Escherichia coli Proteins
Iron-Sulfur Proteins
Journal Article
Sulfur
Sulfurtransferases

Anmerkungen:

Date Completed 25.01.2024

Date Revised 01.02.2024

published: Print-Electronic

Citation Status MEDLINE

doi:

10.1021/jacs.3c05481

funding:

Förderinstitution / Projekttitel:

PPN (Katalog-ID):

NLM367058316