6UFM

Cocrystal Structure of the Nocardia farcinica ileS T-box riboswitch in complex with its cognate tRNA

Summary for 6UFM

• Entry DOI: 10.2210/pdb6ufm/pdb
• Descriptor: RNA (77-MER), RNA (98-MER), SULFATE ION (3 entities in total)
• Functional Keywords: rna, complex
• Biological source: Mycolicibacterium smegmatis; More
• Total number of polymer chains: 2
• Total formula weight: 56726.90

Authors

Suddala, K.C.,Zhang, J. (deposition date: 2019-09-24, release date: 2019-12-04, Last modification date: 2024-04-03)

Primary citation

Suddala, K.C.,Zhang, J.
High-affinity recognition of specific tRNAs by an mRNA anticodon-binding groove.
Nat.Struct.Mol.Biol., 26:1114-1122, 2019

PubMed Abstract: T-box riboswitches are modular bacterial noncoding RNAs that sense and regulate amino acid availability through direct interactions with tRNAs. Between the 5' anticodon-binding stem I domain and the 3' amino acid sensing domains of most T-boxes lies the stem II domain of unknown structure and function. Here, we report a 2.8-Å cocrystal structure of the Nocardia farcinica ileS T-box in complex with its cognate tRNA. The structure reveals a perpendicularly arranged ultrashort stem I containing a K-turn and an elongated stem II bearing an S-turn. Both stems rest against a compact pseudoknot, dock via an extended ribose zipper and jointly create a binding groove specific to the anticodon of its cognate tRNA. Contrary to proposed distal contacts to the tRNA elbow region, stem II locally reinforces the codon-anticodon interactions between stem I and tRNA, achieving low-nanomolar affinity. This study illustrates how mRNA junctions can create specific binding sites for interacting RNAs of prescribed sequence and structure.

PubMed: 31792448
DOI: 10.1038/s41594-019-0335-6

Experimental method

X-RAY DIFFRACTION (2.82 Å)