| Description | Verrucomicrobium spinosum DSM 4136 and Chthoniobacter flavus Ellin428, both members of the Verrucomicrobia, have multiple homologous operons featuring four proteins with similarly narrow species distributions. Three of these families have N-terminal signal sequences typical of type IV pilus modification target proteins (see TIGR02523). The fourth is a large protein, usually > 1300 residues. The majority of these four-gene cassettes are adjacent to a PEP-CTERM protein (see TIGR02595), among the largest PEP-CTERM proteins from any species, with repetitive structure that suggests outer membrane autotransporter function (see TIGR02601). The surface structures that these cassettes may from are not yet understood. |
