6.5.1.8: 3'-phosphate/5'-hydroxy nucleic acid ligase
This is an abbreviated version!
For detailed information about 3'-phosphate/5'-hydroxy nucleic acid ligase, go to the full flat file.
Reaction
Synonyms
3'-P RNL, MXAN_0280, MXAN_4982, RNA-splicing ligase, rtcB, RtcB RNA ligase, Rtcb-1, RtcB1, Trl1, tRNA splicing ligase, tRNA-splicing ligase
ECTree
Advanced search results
General Information
General Information on EC 6.5.1.8 - 3'-phosphate/5'-hydroxy nucleic acid ligase
Please wait a moment until all data is loaded. This message will disappear when all data is loaded.
malfunction
-
RNAi knockdown of rtcb-1 lowers endoplasmic reticulum stress response in vivo
physiological function
archease and RtcB from Pyrococcus horikoshii function in tandem, with Archease altering the catalytic properties of the RNA ligase. Catalytic concentrations of archease are sufficient to activate RtcB, and Archease accelerates both the RNA 3'-P guanylylation and ligation steps. Archease can alter the NTP specificity of RtcB such that ATP, dGTP or ITP is used efficiently. RtcB variants that have inactivating substitutions in the guanine-binding pocket can be rescued by the addition of archease. Substitution of the archease metal-binding residues drastically reduces archease-dependent activation of RtcB
physiological function
enzyme catalyzes the GTP-dependent ligation of RNA with 3'-phosphate and 5'-hydroxyl termini. RtcB can ligate RNA cleaved by RNA endonucleases, which generate 2',3'-cyclic phosphate and then 3'-phosphate termini on one strand, and a 5'-hydroxyl terminus on another strand
physiological function
RtcB as the primary unfolded protein response RNA ligase. In RtcB knockout cells, unconventional XBP1 mRNA splicing is defective during ER stress. The RNA ligase activity of RtcB is directly required for the splicing of XBP1 mRNA
physiological function
-
RtcB from Thermobifida fusca is a single-turnover enzyme that is unable to be converted into a multiple-turnover ligase by archease from other organisms
physiological function
-
RtcB from Thermus thermophilus displays a strong dependency on Archease for maximal activity and can catalyze multiple turnovers only in the presence of archease. Archease from P. horikoshii can activate Thermus thermophilus RtcB
physiological function
RtcB guanylylation precedes the cyclic phosphodiesterase and 3'-phosphate ligase steps of the RNA splicing pathway
physiological function
RtcB is able in vivo to complement growth of yeast cells that lack the endogenous healing/sealing-type tRNA ligase Trl1. RtcB also protects yeast Trl1 mutant cells against a fungal ribotoxin that incises the anticodon loop of cellular tRNAs. RtcB can replace Trl1 as the catalyst of HAC1 mRNA splicing during the unfolded protein response
physiological function
RtcB ligates 3'-monophosphate and 5'-OH ends and has an intrinsic 2',3'-cyclic phosphodiesterase activity. The 2',3'-cyclic phosphodiesterase and ligase reactions both require manganese and are abolished by mutation of the RtcB active site. RtcB executes a unique two-step pathway of strand joining whereby the 2',3'-cyclic phosphodiester end is hydrolyzed to a 3'-monophosphate, which is then linked to the 5'-OH end to form the splice junction. The energy for the 3'-phosphate ligase activity is provided by GTP
physiological function
RtcB ligates the xbp-1 mRNA during the IRE-1 branch of the unfolded protein response. Without RtcB, protein stress results in the accumulation of unligated xbp-1 mRNA fragments, defects in the unfolded protein response, and decreased lifespan. RtcB also ligates endogenous pre-tRNA halves, and RtcB mutants have defects in growth and lifespan that can be bypassed by expression of pre-spliced tRNAs. Animals that lack RtcB have defects that are independent of tRNA maturation and the unfolded protein response
physiological function
upon ER stress, HAC1/XBP1 undergoes exon/intron-specific excision by inositol requiring enzyme 1 to remove an intron and liberate the 5' and 3' exons, which are ligated by tRNA ligase. Expression of RtcB alone in a Saccharomyces cerevisiae tRNA ligase mutant strain inefficiently complements HAC1/XBP1 splicing and the RtcB cofactor archease is required to promote enzymatic activity of RtcB to catalyse RNA ligation
physiological function
-
upon ER stress, HAC1/XBP1 undergoes exon/intron-specific excision by inositol requiring enzyme 1 to remove an intron and liberate the 5' and 3' exons, which are ligated by tRNA ligase. Expression of RtcB in a Saccharomyces cerevisiae tRNA ligase mutant strain is able to complement HAC1/XBP1 splicing
physiological function
-
fungal tRNA ligase Trl1 is an essential enzyme that repairs RNA breaks with 2',3'-cyclic-PO4 and 5'-OH ends inflicted during tRNA splicing and noncanonical mRNA splicing in the fungal unfolded protein response
physiological function
-
the enzyme is a critical regulator of neuronal growth potential and inhibits axon regeneration
physiological function
-
the enzyme operates during the unfolded protein response
physiological function
-
the enzyme operates during the unfolded protein response
physiological function
the enzyme operates during the unfolded protein response
physiological function
the enzyme operates during the unfolded protein response
physiological function
the enzyme operates during the unfolded protein response
physiological function
-
the enzyme protects Caenorhabditis elegans dopamine neurons from age-dependent degeneration induced by human alpha-synuclein or 6-hyroxydopamine
physiological function
-
the enzyme operates during the unfolded protein response
-
physiological function
-
archease and RtcB from Pyrococcus horikoshii function in tandem, with Archease altering the catalytic properties of the RNA ligase. Catalytic concentrations of archease are sufficient to activate RtcB, and Archease accelerates both the RNA 3'-P guanylylation and ligation steps. Archease can alter the NTP specificity of RtcB such that ATP, dGTP or ITP is used efficiently. RtcB variants that have inactivating substitutions in the guanine-binding pocket can be rescued by the addition of archease. Substitution of the archease metal-binding residues drastically reduces archease-dependent activation of RtcB
-