| Type: | Domain | Name: | Phosphoesterase, HXTX |
| Description: | This entry represents a domain found in a number of known and predicted phosphoesterases. These include bacterial and archaeal 2',5' RNA ligases, and a family of predicted phosphoesterases known as the YjcG family. The 2',5' RNA ligases perform a reversible, ATP-independent 2'-5'-ligation of what is presumably a non-phyiological substrate: half-tRNA splice intermediates from an intron-containing yeast tRNA []. The physiological substrate(s) in prokaryotes may include small 2',5'-link-containing oligonucleotides, perhaps with regulatory or biosynthetic roles. This domain contains a conserved HXTX motif which is thought to be important for catalytic activity, as it is in the related enzyme cyclic nucleotide phosphodiesterase (CPDase) []. In 2',5' RNA ligase this domain is duplicated, with the two conserved motifs forming the proposed active site, which is analogous to that of CPDase []. | Short Name: | Phosphoesterase_HXTX |
