title: Crystal structure of biotin synthase, an S-adenosylmethionine-dependent radical enzyme.
abstract: 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.
authors.affiliation: Department of Chemistry, Massachusetts Institute of Technology, Cambridge, MA 02139, USA.
authors.forename: Frederick
authors.initials: F
authors.lastname: Berkovitch
authors.forename: Yvain
authors.initials: Y
authors.lastname: Nicolet
authors.forename: Jason T
authors.initials: JT
authors.lastname: Wan
authors.forename: Joseph T
authors.initials: JT
authors.lastname: Jarrett
authors.forename: Catherine L
authors.initials: CL
authors.lastname: Drennan
mesh_terms: D020816:Amino Acid Motifs; D001665:Binding Sites; D001710:Biotin / Q000031:analogs & derivatives* / Q000737:chemistry* / Q000378:metabolism; D002384:Catalysis; D003460:Crystallization; D018360:Crystallography, X-Ray; D019281:Dimerization; D004926:Escherichia coli / Q000201:enzymology*; D029968:Escherichia coli Proteins / Q000737:chemistry* / Q000378:metabolism*; D006859:Hydrogen / Q000737:chemistry; D006860:Hydrogen Bonding; D007501:Iron / Q000737:chemistry; D008024:Ligands; D008958:Models, Molecular; D011485:Protein Binding; D011487:Protein Conformation; D017510:Protein Folding; D017433:Protein Structure, Secondary; D017434:Protein Structure, Tertiary; D012436:S-Adenosylmethionine / Q000737:chemistry* / Q000378:metabolism; D013455:Sulfur / Q000737:chemistry; D013466:Sulfurtransferases / Q000737:chemistry* / Q000378:metabolism*
chemical_list: D029968:Escherichia coli Proteins; D008024:Ligands; D001710:Biotin; D013455:Sulfur; C004749:desthiobiotin; D012436:S-Adenosylmethionine; D006859:Hydrogen; D007501:Iron; D013466:Sulfurtransferases; C087072:biotin synthase, E coli