{"doi":"10.1093/nar/gkab1260","title":"The C nucleotide at the mature 5′ end of the <i>Escherichia coli</i> proline tRNAs is required for the RNase E cleavage specificity at the 3′ terminus as well as functionality","abstract":"Proline tRNA 3'-maturation in Escherichia coli occurs through a one-step RNase E endonucleolytic cleavage immediately after the CCA determinant. This processing pathway is distinct from the 3'-end maturation of the other tRNAs by avoiding the widespread use of 3' → 5' exonucleolytic processing, 3'-polyadenylation and subsequent degradation. Here, we show that the cytosine (C) at the mature 5'-terminus of the proK and proL tRNAs is required for both the RNase E cleavage immediately after the CCA determinant and their functionality. Thus, changing the C nucleotide at the mature 5'-terminus of the proL and proK tRNAs to the more common G nucleotide led to RNase E cleavages 1-4 nucleotides downstream of the CCA determinant. Furthermore, the 5'-modified mutant tRNAs required RNase T and RNase PH for their 3'-maturation and became substrates for polyadenylation and degradation. Strikingly, the aminoacylation of the 5'-modified proline tRNAs was blocked due to the change in the recognition element for prolyl-tRNA-synthetase. An analogous modification of the pheV 5'-mature terminus from G to C nucleotide did not support cell viability. This result provides additional support for the importance of first nucleotide of the mature tRNAs in their processing and functionality.","journal":"Nucleic Acids Research","year":2021,"id":203153,"datarank":0.0,"base_score":0.0,"endowment":0.0,"self_citation_contribution":0.0,"citation_network_contribution":0.0,"self_endowment_contribution":0.0,"citer_contribution":0.0,"corpus_percentile":null,"corpus_rank":null,"citation_count":6,"citer_count":0,"citers_with_citation_signal":0,"citers_with_endowment":0,"datacite_reuse_total":0,"is_dataset":false,"is_dataset_confidence":0.9527,"is_data_producer":false,"deposit_databanks":null,"is_oa":true,"file_count":0,"downloads":0,"has_version_chain":false,"published_date":"2021-01-01","fair_score":null,"fair_percentile":null,"algorithm_id":"datarank_citation_only_1hop_v6","ranking_scope":"data_only","authors":[{"id":784367,"name":"Valerie F. Maples","orcid":null,"position":1,"is_corresponding":false},{"id":495981,"name":"Sidney R. Kushner","orcid":"0000-0001-6961-6530","position":2,"is_corresponding":false},{"id":496763,"name":"Bijoy K. Mohanty","orcid":null,"position":0,"is_corresponding":true}],"reference_count":35,"raw_metadata":null,"created_at":"2026-07-18T23:51:14.206397Z","pmid":"35061897","pmcid":null,"fwci":null,"citation_percentile":null,"influential_citations":0,"oa_status":null,"license":null,"views":0,"total_file_size_bytes":0,"version_count":0,"fair_f":null,"fair_a":null,"fair_i":null,"fair_r":null,"fair_zscore":null,"fair_rationale":null,"fair_model":null,"fair_agent_version":null,"fair_fulltext_source":null,"fair_has_llm":null,"fair_computed_at":null,"clinical_trials":[],"software_tools":[],"db_accessions":[],"linked_datasets":[],"topics":[]}