吸收破坏性信号

A structure-based approach identifies bacteriophage proteins that block bacterial immunity Iana Fedorova and Joseph Bondy-Denomy Bacteria have multiple systems that provide defense against bacterial viruses (phages). During infection by bacteriophages, specialized bacterial enzymes modify nucleotides or generate cyclic nucleotides, which bind to and activate effector proteins that inhibit phage replication. Thoeris, CBASS (cyclic oligonucleotide–based antiphage signaling systems), Pycsar (pyrimidine cyclase system for antiphage resistance), and type III CRISPR-Cas are examples of these signaling systems. However, phages have evolved inhibitors of these bacterial defense systems, including enzymes that cleave cyclic nucleotides (1, 2). Phages also produce “sponge proteins” that bind to cyclic nucleotide signals, inactivating antiphage immune responses. On page 1008 of this issue, Tal et al. …