T4 RNA Ligase 2, truncated K227Q - 2000 units

T4 RNA Ligase 2, truncated K227Q (T4 Rnl2tr K227Q) specifically ligates the pre-adenylated 5' end of DNA or RNA to the 3' OH end of RNA. The enzyme does not use ATP for ligation but requires pre-adenylated linkers. T4 Rnl2tr K227Q is a point mutant of T4 RNA Ligase 2, truncated (NEB# M0242) . Mutation of K227 in T4 RNA Ligase 2 reduces enzyme lysyl adenylation. This mutation further reduces the formation of undesired ligation products (concatemers and circles) by T4 Rnl2tr, possibly by reducing the trace activity of T4 Rnl2tr in transfer of adenylyl groups from linkers to the 5-phosphates of input RNAs. The exclusion of ATP, use of pre-adenylated linkers, and the reduced enzyme lysyl adenylation activity provide the lowest possible background in ligation reactions. This enzyme has been used for optimized linker ligation for the cloning of microRNAs.