TY - JOUR T1 - In vitro reconstitution of RNA primer removal in Archaea reveals the existence of two pathways A1 - Henneke,Ghislaine AD - IFREMER, UMR 6197, Lab Microbiol Environm Extremes, F-29280 Plouzane, France. AD - Univ Bretagne Occidentale, UMR 6197, Lab Microbiol Environm Extremes, F-29280 Plouzane, France. AD - Ctr Natl Rech Sci, UMR 6197, Lab Microbiol Environm Extremes, F-29280 Plouzane, France. UR - https://doi.org/10.1042/BJ20120959 DO - 10.1042/BJ20120959 KW - Archaea KW - DNA ligase KW - DNA polymerase KW - nuclease KW - Okazaki fragment N2 - Using model DNA substrates and purified recombinant proteins from Pyrococcus abyssi. I have reconstituted the enzymatic reactions involved in RNA primer elimination in vitro. In my dual-labelled system, polymerase D performed efficient strand displacement DNA synthesis, generating 5'-RNA flaps which were subsequently released by Fen1, before ligation by Lig1. In this pathway, the initial cleavage event by RNase HII facilitated RNA primer removal of Okazaki fragments. In addition, I have shown that polymerase B was able to displace downstream DNA strands with a single ribonucleotide at the 5'-end, a product resulting from a single cut in the RNA initiator by RNase HII. After RNA elimination, the combined activities of strand displacement DNA synthesis by polymerase B and flap cleavage by Fen1 provided a nicked substrate for ligation by Lig1. The unique specificities of Okazaki fragment maturation enzymes and replicative DNA polymerases strongly support the existence of two pathways in the resolution of RNA fragments. Y1 - 2012/10 PB - Portland Press Ltd JF - Biochemical Journal SN - 0264-6021 VL - 447 SP - 271 EP - 280 ID - 21841 ER -