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Publication Abstract from PubMed

T-box riboregulators are a class of cis-regulatory RNAs that govern the bacterial response to amino acid starvation by binding, decoding and reading the aminoacylation status of specific transfer RNAs. Here we provide a high-resolution crystal structure of a full-length T-box from Mycobacterium tuberculosis that explains tRNA decoding and aminoacylation sensing by this riboregulator. Overall, the T-box consists of decoding and aminoacylation sensing modules bridged by a rigid pseudoknot structure formed by the mid-region domains. Stem-I and the Stem-II S-turn assemble a claw-like decoding module, while the antiterminator, Stem-III, and the adjacent linker form a tightly interwoven aminoacylation sensing module. The uncharged tRNA is selectively recognized by an unexpected set of favorable contacts from the linker region in the aminoacylation sensing module. A complex structure with a charged tRNA mimic shows that the extra moiety dislodges the linker, which is indicative of the possible chain of events that lead to alternative base-pairing and altered expression output.

Structural basis for tRNA decoding and aminoacylation sensing by T-box riboregulators.,Battaglia RA, Grigg JC, Ke A Nat Struct Mol Biol. 2019 Nov 18. pii: 10.1038/s41594-019-0327-6. doi:, 10.1038/s41594-019-0327-6. PMID:31740853^[1]

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