8ves
Structure of YicC endoribonuclease bound to an RNA substrate
Structural highlights
FunctionYICC_ECOLI Contributes to degradation of small RNA (sRNA) RhyB. Upon overexpression suppresses sRNA-mediated RhyB-silencing of multiple RNA targets but not other sRNA's targets; overexpression leads to loss of RhyB sRNA. Enables degradation of RhyB by 3' to 5' exoribonuclease PNPase (pnp) (PubMed:34210798). Endonucleolytically cleaves ssRNA, probably generating a 3'-OH and a 5'-phosphate group (PubMed:34815358).[1] [2] Publication Abstract from PubMedProcessing of RNA is a key regulatory mechanism for all living systems. Escherichia coli protein YicC belongs to the well-conserved YicC family and has been identified as a novel ribonuclease. Here, we report a 2.8-A-resolution crystal structure of the E. coli YicC apo protein and a 3.2-A-cryo-EM structure of YicC bound to an RNA substrate. The apo YicC forms a dimer of trimers with a large open channel. In the RNA-bound form, the top trimer of YicC rotates nearly 70 degrees and closes the RNA substrate inside the cavity to form a clamshell-pearl conformation that resembles no other known RNases. The structural information combined with mass spectrometry and biochemical data identified cleavage on the upstream side of an RNA hairpin. Mutagenesis studies demonstrated that the previously uncharacterized domain, DUF1732, is critical in both RNA binding and catalysis. These studies shed light on the mechanism of the previously unexplored YicC RNase family. Structural insights into RNA cleavage by a novel family of bacterial RNases.,Wu R, Ingle S, Barnes SA, Dahlin HR, Khamrui S, Xiang Y, Shi Y, Bechhofer DH, Lazarus MB Nucleic Acids Res. 2024 Aug 24:gkae717. doi: 10.1093/nar/gkae717. PMID:39180400[3] From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine. References
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