Archaeal Nucleic Acid Ligases and Their Potential in Biotechnology

Figure 1

Structures of the DNA ligases from: (a) Sulfolobus solfataricus (PDB ID 2HIX); (b) Thermococcus sp. 1519 (PDB ID 3RR5); (c) Pyrococcus furiosus (PDB ID 2CFM); and (d) Homo sapiens (PDB ID 1X9N). The positions of the DNA binding domain (DBD), adenylation domain (AdD), and oligonucleotide binding domain (OBD) are indicated in the S. solfataricus structure. While the DBD and AdD occupy equivalent positions in all of the structures, the S. solfataricus enzyme shows an open extended conformation of the OBD, the Thermococcus sp. 1519 enzyme shows a 90° anticlockwise rotation of the OBD relative to the S. solfataricus enzyme (indicated by a black arrow) resulting in the intermediate conformation, and the P. furiosus ligase has a 120° rotation exhibiting the closed conformation. Human DNA ligase 1 is shown bound to a nicked DNA substrate (light green). The C-terminal helix of each enzyme is highlighted in purple.

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