Emergence of the β-CASP ribonucleases: Highly conserved and ubiquitous metallo-enzymes involved in messenger RNA maturation and degradation

► The review describes the metallo-β-lactamase β-CASP enzymes acting on RNA. ► The β-CASP orthologous groups of the three domains of life are defined. ► The features of eukaryal CPSF73 and bacterial RNase J orthologs are described. ► The role of complex formation for the function of β-CASP ribonucleases is discussed. ► Evolutionary function origins of the β-CASP family are suggested.