Biotin synthase mechanism: on the origin of sulphur.
Biotin synthase catalyses the last step of the biosynthesis of biotin in microorganisms and plants. The active protein isolated from Bacillus sphaericus and Escherichia coli contains an iron-sulphur (FeS) cluster. The native enzymes were depleted of their iron and inorganic sulphide and the resulting apoenzymes were chemically reconstituted with FeCl3 and Na2[34S] to give labelled (Fe34S) enzymes. These enzymes were functional and when assayed in vitro produced labelled biotin containing about 65% of 34S. These data strongly support the hypothesis that the sulphur of biotin is derived from the (FeS) centre of the enzyme.
Bui
B T
BT
Laboratoire de Chimie Organique Biologique, Université Paris VI-CNRS UMR 7613, France.
Florentin
D
D
Fournier
F
F
Ploux
O
O
Méjean
A
A
Marquet
A
A
D001051:Apoenzymes / Q000378:metabolism; D001407:Bacillus / Q000201:enzymology* / Q000378:metabolism; D001426:Bacterial Proteins / Q000378:metabolism; D001710:Biotin / Q000096:biosynthesis* / Q000737:chemistry; D002712:Chlorides; D004926:Escherichia coli / Q000201:enzymology* / Q000378:metabolism; D005290:Ferric Compounds / Q000378:metabolism; D020035:Holoenzymes / Q000378:metabolism; D007501:Iron / Q000378:metabolism; D007700:Kinetics; D013058:Mass Spectrometry; D008956:Models, Chemical; D013440:Sulfides / Q000378:metabolism; D013455:Sulfur / Q000378:metabolism*; D013466:Sulfurtransferases / Q000737:chemistry / Q000378:metabolism*
D001051:Apoenzymes; D001426:Bacterial Proteins; D002712:Chlorides; D005290:Ferric Compounds; D020035:Holoenzymes; D013440:Sulfides; D001710:Biotin; D013455:Sulfur; D007501:Iron; D013466:Sulfurtransferases; C057985:biotin synthetase; C024555:ferric chloride; C033479:sodium sulfide