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Publication Abstract from PubMed

Tpt1 is an essential agent of fungal tRNA splicing that removes the 2'-PO4 at the splice junction generated by fungal tRNA ligase. Tpt1 catalyzes a unique two-step reaction whereby the 2'-PO4 attacks NAD(+) to form an RNA-2'-phospho-ADP-ribosyl intermediate that undergoes transesterification to yield 2'-OH RNA and ADP-ribose-1,2-cyclic phosphate products. Because Tpt1 is inessential in exemplary bacterial and mammalian taxa, Tpt1 is seen as an attractive antifungal target. Here we report a 1.4 A crystal structure of Tpt1 in a product-mimetic complex with ADP-ribose-1-phosphate in the NAD(+) site and pAp in the RNA site. The structure reveals how Tpt1 recognizes a 2'-PO4 RNA splice junction and the mechanism of RNA phospho-ADP-ribosylation. This study also provides evidence that a bacterium has an endogenous phosphorylated substrate with which Tpt1 reacts.

Structure of tRNA splicing enzyme Tpt1 illuminates the mechanism of RNA 2'-PO4 recognition and ADP-ribosylation.,Banerjee A, Munir A, Abdullahu L, Damha MJ, Goldgur Y, Shuman S Nat Commun. 2019 Jan 15;10(1):218. doi: 10.1038/s41467-018-08211-9. PMID:30644400^[1]

From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine.