A nucleosidase required for in vivo function of the S-Adenosyl-L-Methionine radical enzyme, biotin synthase
A nucleosidase required for in vivo function of the S-Adenosyl-L-Methionine radical enzyme, biotin synthase
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DOI：
10.1016/j.chembiol.2005.04.012
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发表时间：
2005-05-01
影响因子：
--
通讯作者：
Cronan, JE
中科院分区：
文献类型：
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作者：
Choi-Rhee, EJ;Cronan, JE
生物素合酶是一种 S-腺苷-L-甲硫氨酸 (SAM) 自由基酶，可将硫插入脱硫生物素中以产生生物素。该反应通过 5' 脱氧腺苷自由基中间体进行，这些中间体在硫插入步骤中被还原，得到反应的另一种产物 5'-脱氧腺苷。我们报道，缺乏 pfs 基因编码的 5'-甲硫腺苷/S-腺苷高半胱氨酸核苷酶的大肠杆菌菌株由于 5'-脱氧腺苷（pfs 编码核苷酶的新底物）的积累而缺乏印迹合酶活性。生理实验表明，硫辛酸合酶（另一种 SAM 自由基酶）也受到 5'-脱氧腺苷积累的抑制。
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 blotin 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.