Conserved Site

RNA 3'-terminal phosphate cyclase-like, conserved site (IPR020719)

Short name: RNA3'_term_phos_cycl-like_CS


RNA cyclases are a family of RNA-modifying enzymes that are conserved in eukaryotes, bacteria and archaea. Type 1 RNA 3'-terminal phosphate cyclases (EC: [PMID: 9184239, PMID: 2199762] catalyse the conversion of 3'-phosphate to a 2',3'-cyclic phosphodiester at the end of RNA:

ATP + RNA 3'-terminal-phosphate = AMP + diphosphate + RNA terminal-2',3'-cyclic-phosphate

The physiological function of the cyclase is not known, but the enzyme could be involved in the maintenance of cyclic ends in tRNA splicing intermediates or in the cyclisation of the 3' end of U6 snRNA [PMID: 9184239].

A second subfamily of RNA 3'-terminal phosphate cyclases (type 2) that do not have cyclase activity have been identified in eukaryotes. They are localised to the nucleolus and are involved in ribosomal modification [PMID: 10790377].

RNA 3'-terminal phosphate cyclases contain a conserved glycine-rich stretch of residues located in the central part of the sequence, which is reminiscent of various ATP, GTP or AMP glycine-rich loops, and may be involved in AMP binding. This entry represents the conserved site.

Contributing signatures

Signatures from InterPro member databases are used to construct an entry.
PROSITE patterns