This is a predicted enzymatic alpha and beta fold domain with a large, prominent helix with conserved glutamate residue and several additional conserved residues including the motifs HTxN and SN [1]. The domain is associated with polyvalent proteins of firmicute conjugative elements [1].

1: Polyvalent Proteins, a Pervasive Theme in the Intergenomic Biological Conflicts of Bacteriophages and Conjugative Elements. Iyer LM, Burroughs AM, Anand S, de Souza RF, Aravind L; J Bacteriol. 2017; [Epub ahead of print] PMID:28559295