Members of this family cleave pre tRNA at the 5' and 3' splice sites to release the intron EC:18.104.22.168.
This entry represents a three-layer alpha/beta/alpha domain found as the catalytic domain at the C-terminal in homotetrameric tRNA-intron endonucleases [PUBMED:9535656], and as domains 2 and 4 (C-terminal) in the homodimeric enzymes [PUBMED:16690865]. tRNA-intron endonucleases (EC) remove tRNA introns by cleaving pre-tRNA at the 5'- and 3'-splice sites to release the intron. The products are an intron and two tRNA half-molecules bearing 2',3' cyclic phosphate and 5'-hydroxyl termini [PUBMED:9200602]. These enzymes recognise a pseudosymmetric substrate in which two bulged loops of three bases are separated by a stem of four bp [PUBMED:14993668]. Although homotetrameric enzymes contain four active sites, only two participate in the cleavage, and should therefore, be considered as a dimer of dimers.
Kleman-Leyer K, Armbruster DW, Daniels CJ; , Cell 1997;89:839-847.: Properties of H. volcanii tRNA intron endonuclease reveal a relationship between the archaeal and eucaryal tRNA intron processing systems. PUBMED:9200602 EPMC:9200602 .
Steczkiewicz K, Muszewska A, Knizewski L, Rychlewski L, Ginalski K;, Nucleic Acids Res. 2012;40:7016-7045.: Sequence, structure and functional diversity of PD-(D/E)XK phosphodiesterase superfamily. PUBMED:22638584 EPMC:22638584.