Work

Independent neofunctionalization of Dxo1 inSaccharomycesandCandidaled to 25S rRNA processing function

Year: 2024

Type: article

Abstract: Eukaryotic genomes typically encode one member of the DXO/Dxo1/Rai1 family of enzymes, which can hydrolyze the 5′ ends of RNAs with a variety of structures that deviate from the canonical7mGpppN. In contrast, theSaccharomycesgenome encodes two family members and the second copy, Dxo1, is a distributive 5′ exoribonuclease that is required for the final maturation of the 5′ end of 25S rRNA from a 25S′ precursor. Here we show that this 25S rRNA maturation function is not conserved across kingdoms, but arose in the budding yeasts. Interestingly, the origin of 25S processing capacity coincides with the duplication of this gene, and this capacity is absent in the nonduplicated genes. Strikingly, two different clades of budding yeasts have undergone parallel evolution: Both duplicated their DXO/Dxo1/Rai1 gene, and in both cases, one copy gained the 25S processing function. This was accompanied by many parallel sequence changes, a remarkable case of reproducible neofunctionalization.

Source: RNA

DOI: 10.1261/rna.080210.124

Authors: Jennifer E. Hurtig, Catherine J. Stuart, Ambro van Hoof

Institutions: The University of Texas MD Anderson Cancer Center, The University of Texas Health Science Center at Houston

Language: English

Topic: RNA Research and Splicing

Subfield: Molecular Biology

Field: Biochemistry, Genetics and Molecular Biology

Domain: Life Sciences

Open Access status: bronze

Funders: Wake Forest University, National Institute of General Medical Sciences

Award: RNase functions in post-transcriptional gene regulation