6yss
From Proteopedia
Structure of the P+9 ArfB-ribosome complex in the post-hydrolysis state
Structural highlights
FunctionC3SR27_ECOLX Located at the back of the 30S subunit body where it stabilizes the conformation of the head with respect to the body (By similarity).[SAAS:SAAS005712_004_009826][HAMAP-Rule:MF_01307] With S4 and S12 plays an important role in translational accuracy (By similarity).[SAAS:SAAS005712_004_003902][HAMAP-Rule:MF_01307] Publication Abstract from PubMedAlternative ribosome-rescue factor B (ArfB) rescues ribosomes stalled on non-stop mRNAs by releasing the nascent polypeptide from the peptidyl-tRNA. By rapid kinetics we show that ArfB selects ribosomes stalled on short truncated mRNAs, rather than on longer mRNAs mimicking pausing on rare codon clusters. In combination with cryo-electron microscopy we dissect the multistep rescue pathway of ArfB, which first binds to ribosomes very rapidly regardless of the mRNA length. The selectivity for shorter mRNAs arises from the subsequent slow engagement step, as it requires longer mRNA to shift to enable ArfB binding. Engagement results in specific interactions of the ArfB C-terminal domain with the mRNA entry channel, which activates peptidyl-tRNA hydrolysis by the N-terminal domain. These data reveal how protein dynamics translate into specificity of substrate recognition and provide insights into the action of a putative rescue factor in mitochondria. Mechanism of ribosome rescue by alternative ribosome-rescue factor B.,Chan KH, Petrychenko V, Mueller C, Maracci C, Holtkamp W, Wilson DN, Fischer N, Rodnina MV Nat Commun. 2020 Aug 14;11(1):4106. doi: 10.1038/s41467-020-17853-7. PMID:32796827[1] From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine. See AlsoReferences
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