Imidazole idz

Restriction endonucleases, DNA polymerases and polynucleotide kinase were purchased from Enzynomics (Daejeon, Korea). Antibodies against hexahistidine (6XHis) epitope or glutathione-S transferase (GST) used for western blotting were from Qiagen (Valencia, CA, USA) and Santa Cruz Biotechnology (Santa Cruz, CA, USA), respectively. Secondary antibodies were from Amersham Biosciences (Piscataway, NJ, USA). Oligonucleotides used in this study were commercially synthesized by Genotech or Macrogen (Daejeon, Korea). All oligonucleotides were gel-purified prior to use. Nucleoside triphosphates were obtained from Sigma-Aldrich (St. Loius, MO, USA), and [γ-³²P]ATP (>3000 Ci/mmol) was purchased from Perkin Elmer NEN (Waltham, MA, USA). The pRS plasmids were purchased from New England Biolabs (Beverly, MA, USA). The pET vectors used for protein expression in Escherichia coli were from Novagen (Darmstadt, Germany). Isopropyl β-D-1-thiogalactopyranoside (IPTG) was from ElpisBiotech (Daejeon, Korea). Imidazole (IDZ) was from Acros Organics (Geel, Belgium). The uracil analog, 5-fluoroorotic acid (5-FOA) and proteinase K were obtained from Duchefa Biochemie (Haarlem, Netherland). MMS was obtained from Sigma-Aldrich (St. Loius, MO, USA).