RNA 3'-terminal phosphate cyclase (RTCA)

RNA 3'-terminal phosphate cyclase (RTCA) is an enzyme that catalyzes the ATP-dependent conversion of a 3'-phosphate group at the end of RNA into a 2',3'-cyclic phosphodiester[1][2][4][5]. The cyclization reaction occurs via a three-step mechanism: (1) formation of a covalent RtcA-AMP intermediate by adenylation of the enzyme, (2) transfer of AMP to the RNA 3'-phosphate to yield RNA(3')pp(5')A, and (3) cyclization forming a 2',3'-cyclic phosphate and releasing AMP[1][2][4][5]. RTCA plays an important role in RNA metabolism and repair, especially tRNA splicing, and is found in a wide range of organisms, including bacteria, archaea, and eukaryotes. Structural studies indicate that RTCA is highly specific for ribonucleotides and uses conserved catalytic residues for covalent catalysis and substrate recognition[1][3][4]. There is no evidence it is currently a direct therapeutic target or clinical biomarker.

Other names

RTCARPCRPC1RTC1RTCD1RNA cyclaseRNA-3'-phosphate cyclaseRTC domain-containing protein 1RNA terminal phosphate cyclase domain-containing protein 1

no drugs reported; enzyme acts by formation of covalent RtcA–AMP intermediate, adenylate transfer, and cyclization in RNA metabolism