Crystal Structure of Biotin Synthase, an S-Adenosylmethionine-Dependent Radical Enzyme

+ See all authors and affiliations

Science  02 Jan 2004:
Vol. 303, Issue 5654, pp. 76-79
DOI: 10.1126/science.1088493

You are currently viewing the abstract.

View Full Text


The crystal structure of biotin synthase from Escherichia coli in complex with S-adenosyl-L-methionine and dethiobiotin has been determined to 3.4 angstrom resolution. This structure addresses how “AdoMet radical” or “radical SAM” enzymes use Fe4S4 clusters and S-adenosyl-L-methionine to generate organic radicals. Biotin synthase catalyzes the radical-mediated insertion of sulfur into dethiobiotin to form biotin. The structure places the substrates between the Fe4S4 cluster, essential for radical generation, and the Fe2S2 cluster, postulated to be the source of sulfur, with both clusters in unprecedented coordination environments.

View Full Text