PADLOC is a bioinformatics resource developed by the Jackson Lab at the University of Otago in Aotearoa New Zealand. Its name stands for Prokaryotic Antiviral Defence LOCator, reflecting its focus on helping researchers identify antiviral defence systems in microbial genomes. The PADLOC web server provides tools to run analyses, view results, and explore information about defence systems. Users can also browse precomputed data, including RefSeq results, and consult PADLOC-DB, a database of identified systems.

PADLOC-DB version 2.0.0 includes newly reported candidate systems, such as HEC systems and hundreds of additional PDC systems. These candidates were identified using a “guilt-by-embedding” approach, which infers possible defence functions for proteins encoded within known defence systems. The project also offers a command-line tool for analysis. PADLOC’s web server and software are described in peer-reviewed research publications, and the site provides citation details for researchers using its resources. Together, these offerings support the identification and classification of antiviral defence systems in bacteria and archaea.