TY  - JOUR
AU  - Kim, Soo-Kyoung
AU  - Orr, Mona
AU  - Turdiev, Husan
AU  - Jenkins, Conor
AU  - Lormand, Justin David
AU  - Myers, Tanner
AU  - Burnim, Audrey
AU  - Carter, Jared
AU  - Husseini, Nour El
AU  - Kung, Warren
AU  - Jiang, Xiaofang
AU  - Sondermann, Holger
AU  - Winkler, Wade
AU  - Lee, Vincent
TI  - Diribonuclease activity eliminates toxic diribonucleotide accumulation
JO  - Cell reports
VL  - 43
IS  - 9
SN  - 2211-1247
CY  - [New York, NY]
PB  - Elsevier
M1  - PUBDB-2024-05706
SP  - 114759
PY  - 2024
AB  - RNA degradation is a central process in cells, which is vital for transcriptional regulation. The degradation process is initiated by endoribonucleolytic fragmentation of long RNA polymers, followed by exoribonucleolytic cleavage to release mononucleotides from the fragment ends. In this process, the degradation of short oligonucleotides, especially diribonucleotides, into mononucleotides requires specific enzymatic activity, which in Gram-negative bacteria is provided by oligoribonuclease (Orn). Orn is unique in that it is the only essential exoribonuclease in Escherichia coli. Recent studies have shown that Orn cleaves only diribonucleotides under physiological conditions, suggesting that the accumulation of dinucleotides poisons cells. Yet, related organisms, such as Pseudomonas aeruginosa, display a growth defect but are viable without Orn, contesting its essentiality. Here, we took advantage of P. aeruginosa orn mutants to elucidate the mechanisms of their survival. Genetic screening for suppressors that restored colony morphology identified yciV. Purified YciV exhibited diribonuclease activity. YciV is present in all γ-proteobacteria, suggesting that the enzyme from P. aeruginosa is distinct from its E. coli ortholog. Phylogenetic analysis revealed differences between the two orthologs that were mapped to the active site of the enzyme and correlated with differences in substrate profiles. The expression of P. aeruginosa YciV in E. coli eliminated the necessity of orn. Similarly, the deletion of yciV from P. aeruginosa caused orn to become essential. Together, these results show that diribonuclease activity is required in γ-proteobacteria and that diribonucleotides may be utilized to monitor the efficacy of RNA degradation. Because Orn is found in higher eukaryotes, these observations indicate a conserved mechanism for monitoring RNA degradation. 
LB  - PUB:(DE-HGF)16
C6  - 39276351
UR  - <Go to ISI:>//WOS:001318568400001
DO  - DOI:10.1016/j.celrep.2024.114759
UR  - https://bib-pubdb1.desy.de/record/613927
ER  -