NMR structure of the Bordetella bronchiseptica protein NP_888769.1 establishes a new phage‐related protein family PF13554

The solution structure of the hypothetical phage‐related protein NP_888769.1 from the Gram‐negative bacterium Bordetella bronchoseptica contains a well‐structured core comprising a five‐stranded, antiparallel β‐sheet packed on one side against two α‐helices and a short β‐hairpin with three flexibly disordered loops extending from the central β‐sheet. A homology search with the software DALI identified two Protein Data Bank deposits with Z‐scores > 8, where both of these proteins have less than 8% sequence identity relative to NP_888769.1, and one has been functionally annotated as a lambda phage tail terminator protein. A sequence‐homology analysis then confirmed that NP_888769.1 represents the first three‐dimensional structural representative of a new protein family that was previously predicted by the Joint Center for Structural Genomics, which includes so far about 20 prophage proteins encoded in bacterial genomes.