GIY-YIG domain of LuxR and ArsR family transcriptional regulators, and uncharacterized hypothetical proteins found in bacteria
The family includes some bacterial LuxR and ArsR family transcriptional regulators. The a C-terminal conserved domain shows sequence similarity to the N-terminal catalytic GIY-YIG domains of intron-encoded homing endonucleases. Besides, they have an N-terminally fused transcriptional regulators module, comprising the winged helix-turn-helix (wHTH) domain and uncharacterized domain DUF2087. At this point, they are distinct from GIY-YIG homing endonucleases, which typically contain a variety of C-terminally fused nuclease-associated modular DNA-binding domains (NUMODs). Moreover, some key residues relevant to catalysis in GIY-YIG endonucleases are mutanted or absent in this family, which suggests that members in this family might lose the catalytic function that GIY-YIG endonucleases possess. This family also includes many uncharacterized hypothetical proteins that consist of a standalone GIY-YIG like domain.
Jiyao W et al.(2023). "The conserved domain database in 2023.",