This domain is found in the gene transfer agent protein. An unusual system of genetic exchange exists in the purple nonsulfur bacterium Rhodobacter capsulatus. DNA transmission is mediated by a small bacteriophage-like particle called the gene transfer agent (GTA) that transfers random 4.5-kb segments of the producing cell's genome to recipient cells, where allelic replacement occurs [1]. The genes involved in this process appear to be found widely in bacteria [2]. According to the SUPERFAMILY database this domain has a TIM barrel fold.

1: Genetic analysis of a bacterial genetic exchange element: the gene transfer agent of Rhodobacter capsulatus. Lang AS, Beatty JT; Proc Natl Acad Sci U S A. 2000;97:859-864. PMID:10639170

2: Importance of widespread gene transfer agent genes in alpha-proteobacteria. Lang AS, Beatty JT; Trends Microbiol. 2007;15:54-62. PMID:17184993