Chlamydia trachomatis‐derived deubiquitinating enzymes in mammalian cells during infection

Summary Chlamydia trachomatis is an obligate intracellular bacterium that causes a variety of diseases in humans. C. trachomatis has a complex developmental cycle that depends on host cells for replication, during which gene expression is tightly regulated. Here we identify two C. trachomatis proteases that possess deubiquitinating and deneddylating activities. We have designated these proteins ChlaDub1 and ChlaDub2. The genes encoding ChlaDub1 and ChlaDub2 are present in all Chlamydia species except for Chlamydia pneumoniae, and their catalytic domains bear similarity to the catalytic domains of other eukaryotic ubiquitin‐like proteases (Ulp). The C. trachomatis DUBs react with activity‐based probes and hydrolyse ubiquitinated and neddylated substrates. ChlaDub1 and ChlaDub2 represent the first known bacterial DUBs that possess both deubiquitinating and deneddylating activities.