This family describes the exodeoxyribonuclease V alpha subunit, RecD. RecD is part of a RecBCD complex. A related family in the Gram-positive bacteria separates in a phylogenetic tree, has an additional N-terminal extension of about 200 residues, and is not supported as a member of a RecBCD complex by neighboring genes. The related family is consequently described by a different model. [DNA metabolism, DNA replication, recombination, and repair]