Virtuelle (Nano) Welten: PDB Molecule of the Month 33: Reverse Transcriptase

Two Enzymes in One

Reverse transcriptase performs several different functions. As indicated by the name, it can build DNA strands based on an RNA template. This reaction is performed in the polymerase active site, which is formed by two sets of arms that surround the RNA and DNA. The polymerase site is at the top in this illustration, taken from PDB entry 2hmi. After building the DNA strand, the enzyme then removes the original RNA strand by cleaving it into pieces. This is performed by a nuclease active site, which is located at the opposite end of the enzyme. Finally, it builds a second DNA strand matched to the one that was just created to form the final DNA double helix. This reaction is also performed by the polymerase site.