RNA-3'-phosphate cyclase

In enzymology, a RNA-3′-phosphate cyclase (EC 6.5.1.4) is an enzyme that catalyzes the chemical reaction

ATP + RNA 3'-terminal-phosphate ${\displaystyle \rightleftharpoons }$ AMP + diphosphate + RNA terminal-2',3'-cyclic-phosphate

RNA-3′-phosphate cyclase
Identifiers
EC no.	6.5.1.4
CAS no.	85638-41-1
Databases
IntEnz	IntEnz view
BRENDA	BRENDA entry
ExPASy	NiceZyme view
KEGG	KEGG entry
MetaCyc	metabolic pathway
PRIAM	profile
PDB structures	RCSB PDB PDBe PDBsum
Gene Ontology	AmiGO / QuickGO
Search PMC articles PubMed articles NCBI proteins

Thus, the two substrates of this enzyme are ATP and RNA 3'-terminal-phosphate, whereas its 3 products are AMP, diphosphate, and RNA terminal-2',3'-cyclic-phosphate.

This enzyme belongs to the family of ligases, specifically those forming phosphoric-ester bonds. The systematic name of this enzyme class is RNA-3'-phosphate:RNA ligase (cyclizing, AMP-forming). This enzyme is also called RNA cyclase.

Structural studies

As of 2010, three structures have been solved for this class of enzymes, with PDB accession codes 1QMH​ and 1QMI​, (un-adenylated)^[1] and 3KGD​ (adenylated).^[2]