Fatty acid desaturase protein family subgroup, a delta-12 acyl-lipid desaturase-like, DesA-like, yet uncharacterized subgroup of membrane fatty acid desaturase proteins found in alpha-, beta-, and gamma-proteobacteria. Sequences of this domain family appear to be structurally related to membrane fatty acid desaturases and alkane hydroxylases. They all share in common extensive hydrophobic regions that would be capable of spanning the membrane bilayer at least twice. Comparison of these sequences also reveals three regions of conserved histidine cluster motifs that contain eight histidine residues: HXXXH, HXXHH, and HXXHH. These histidine residues are reported to be catalytically essential and proposed to be the ligands for the iron atoms contained within homologs, stearoyl CoA desaturase and alkane hydroxylase.
Jiyao W et al.(2023). "The conserved domain database in 2023.",