This family consists mostly of short uncharacterized proteins found in various high GC Gram positive bacteria, primarily Mycobacterium species. However in some proteins, such as for instance Rv0943c proteins from Mycobacterium tuberculosis H37Rv, DUF4873 domain is found at the C-terminus, following the flavin-binding monooxygenase-like domain Pfam:PF00743, which is why probably many proteins with DUF4873 domains are annotated as monooxygenases. However these functions are not confirmed experimentally and the function of DUF4873 domain is still unknown.