Direct evidence for enzyme persulfide and disulfide intermediates during 4-thiouridine biosynthesis.
نویسندگان
چکیده
Two proposed mechanisms for 4-thiouridine generation share key cysteine persulfide and disulfide intermediates, and indirect evidence of their existence has been previously reported; chemical trapping and mass spectrometry have now provided direct and definitive evidence of these key intermediates.
منابع مشابه
A paradigm for biological sulfur transfers via persulfide groups: a persulfide-disulfide-thiol cycle in 4-thiouridine biosynthesis.
In support of the key features of sulfur transfer in the proposed mechanisms of 4-thiouridine generation, the enzyme ThiI can turn over only once in the absence of reductants of disulfide bonds, and Cys-456 of ThiI receives the sulfur transferred from the persulfide group of the sulfurtransferase IscS.
متن کاملEvidence that ThiI, an enzyme shared between thiamin and 4-thiouridine biosynthesis, may be a sulfurtransferase that proceeds through a persulfide intermediate.
ThiI is an enzyme common to the biosynthetic pathways leading to both thiamin and 4-thiouridine in tRNA. Comparison of the ThiI sequence with protein sequences in the data bases revealed that the Escherichia coli enzyme contains a C-terminal extension displaying sequence similarity to the sulfurtransferase rhodanese. Cys-456 of ThiI aligns with the active site cysteine residue of rhodanese that...
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Sulfur is an essential element for a variety of cellular constituents in all living organisms. In tRNA molecules, there are many sulfur-containing nucleosides, such as the derivatives of 2-thiouridine (s(2)U), 4-thiouridine (s(4)U), 2-thiocytidine (s(2)C), and 2-methylthioadenosine (ms(2)A). Earlier studies established the functions of these modifications for accurate and efficient translation,...
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Post-translational tRNA modifications have very broad diversity and are present in all domains of life. They are important for proper tRNA functions. In this review, we emphasize the recent advances on the biosynthesis of sulfur-containing tRNA nucleosides including the 2-thiouridine (s²U) derivatives, 4-thiouridine (s⁴U), 2-thiocytidine (s²C), and 2-methylthioadenosine (ms²A). Their biosynthet...
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عنوان ژورنال:
- Chemical communications
دوره 29 شماره
صفحات -
تاریخ انتشار 2006