9.B.153 The Putative Beta-Barrel Porin/Alpha Amylase (BBP/AA) Family
The BBP/AA family consists of proteins predicted to consist of outer membane beta-barrels. However they are often annotated in the NCBI protein database as the DUF1551 or PF04314 family, alpha-amylase catalytic proteins, members of the Phenol_MetA-deg (MetA-pathway of phenol degradation) superfamily, signal peptide proteins and porins. These proteins are numerous and present in a wide range of Gram-negative bacteria. Some have C-terminal peptidoglycan-binding OmpA-like domains as well as other domains, and have sizes that can be as small as 300 aas and as large as 900 aas. They show sequence similarity with other families such as 9.B.186 and 9.B.170 which may all have an OmpA peptidoglycan-binding domain. Although these proteins are listed as members of the Outer Membrane Pore-forming Protein (OMPP-I) Superfamily , it is not certain that they show sequence similarity in their putative porin domains.