RNA ligases

Ligation The enzyme-catalyzed joining in phos-phodiester linkage of two stretches of DNA or RNA into one the respective enzymes are DNA and RNA ligases. 

The authors obtained an RNA ligase ribozyme using the method of in vitro evolution . Here, macromolecules are allowed to go through a series of synthetic cycles, which are followed by a proliferation phase, mutation and selection. As in Darwinian evolution, the goal is to carry out laboratory selection of molecules with certain required properties. 

Substrate-ligase EC6.5 Forming Phosphoric Ester Bonds (DNA ligase (ATP), RNA ligase (ATP), etc.) ... 

Reetz et al. described the solid-phase enzymatic synthesis of oligonucleotides on Kieselguhr-PDMA-resins via T4 RNA ligase. Goncomitantly, they found that RNase A selectively cleaves the last bound nucleotide at the ribose sugar leaving a 3, 5 - diphosphorylated ohgomer on the resin, but application in synthesis has not yet been undertaken [22]. 

Furthermore, synthetic oligonucleotide blocks were connected by the same RNA ligase, culminating in the synthesis of E. coli tRNAf and of modified tRNA s. ... 

RIBOSEPHOSPHATE PYROPHOSPHO-KINASE RNA LIGASE RNA POLYMERASE RUBBER cis-POLYPRENYLCISTRANS-FERASE... 

MICROTUBULE ASSEMBLY KINETICS RITCHIE EQUATION RNA, exonucleolytic cleavage, PHOSPHODIESTERASES RNA LIGASE RNA POLYMERASES EDITING MECHANISMS REPLICASE RNA stability,... 

Ekland, E.H., Szostak, J.W., Bartel, D.P. (1995). Structurally complex and highly active RNA ligases derived from random RNA sequences. Science 269, 364-370. 

Despite these clear advantages, the efficiency of splinted RNA ligation reactions catalyzed by T4 DNA ligase is typically limited by the amount of enzyme one can introduce into the reaction. This problem is derived from the poor turnover of T4 DNA ligase on DNA/RNA heteroduplexes. More recently, a variant of T4 RNA ligase, called T4 RNA ligase 2 (Nandakumar et al, 2004), has been identified. This enzyme has a pronounced preference... 

Nandakumar, J., et al. (2004). RNA substrate specificity and structure-guided mutational analysis of bacteriophage T4 RNA ligase 2.J. Biol. Chem. 279, 31337—31347. 

Ho, C. K., and Shuman, S. (2002). Bacteriophage T4 RNA ligase 2 (gp24.1) exemplifies a family ofRNA ligases found in all phylogenetic domains. Proc. Natl. Acad. Sci. USA 99, 12709-12714. 

P-Radiolabeled RNA substrate to be cleaved (prepared by reaction of the RNA with y-32P-ATP and T4 polynucleotide kinase alternatively, 3/-32P-radiolabeling with 32P-pCp and T4 RNA ligase can be used)... 

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