title: A nucleosidase required for in vivo function of the S-adenosyl-L-methionine radical enzyme, biotin synthase.
abstract: Biotin synthase is an S-adenosyl-L-methionine (SAM) radical enzyme that inserts sulfur into dethiobiotin to produce biotin. The reaction proceeds through 5'-deoxyadenosyl radical intermediates that become reduced during the sulfur insertion step to give another product of the reaction, 5'-deoxyadenosine. We report that Escherichia coli strains lacking the 5'-methylthioadenosine/S-adenosylhomocysteine nucleosidase encoded by the pfs gene are deficient in biotin synthase activity due to accumulation of 5'-deoxyadenosine, a new substrate of the pfs-encoded nucleosidase. Physiological experiments indicate that lipoic acid synthase, another SAM radical enzyme, is also inhibited by 5'-deoxyadenosine accumulation.
authors.affiliation: Department of Microbiology, University of Illinois, Urbana 61801, USA.
authors.forename: Eunjoo
authors.initials: E
authors.lastname: Choi-Rhee
authors.forename: John E
authors.initials: JE
authors.lastname: Cronan
mesh_terms: D001710:Biotin / Q000031:analogs & derivatives / Q000494:pharmacology; D003839:Deoxyadenosines / Q000494:pharmacology*; D004926:Escherichia coli / Q000201:enzymology* / Q000235:genetics / Q000254:growth & development; D029968:Escherichia coli Proteins / Q000037:antagonists & inhibitors* / Q000378:metabolism; D009154:Mutation; D009699:N-Glycosyl Hydrolases / Q000235:genetics / Q000378:metabolism*; D013466:Sulfurtransferases / Q000037:antagonists & inhibitors* / Q000378:metabolism
chemical_list: D003839:Deoxyadenosines; D029968:Escherichia coli Proteins; C033714:5'-deoxyadenosine; D001710:Biotin; C004749:desthiobiotin; D013466:Sulfurtransferases; C116435:lipoic acid synthase; C087072:biotin synthase, E coli; D009699:N-Glycosyl Hydrolases; C019606:adenosylhomocysteine nucleosidase