| Type: | Domain | Name: | Riboflavin kinase domain, CTP-dependent |
| Description: | Riboflavin is converted into catalytically active cofactors (FAD and FMN) by the actions of riboflavin kinase (), which converts it into FMN, and FAD synthetase (), which adenylates FMN to FAD. Eukaryotes usually have two separate enzymes, while most prokaryotes have a single bifunctional protein that can carry out both catalyses, although exceptions occur in both cases. While eukaryotic monofunctional riboflavin kinase is orthologous to the bifunctional prokaryotic enzyme [], the monofunctional FAD synthetase differs from its prokaryotic counterpart, and is instead related to the PAPS-reductase family []. The bacterial FAD synthetase that is part of the bifunctional enzyme has remote similarity to nucleotidyl transferases and, hence, it may be involved in the adenylylation reaction of FAD synthetases [].This entry represents a CTP-dependent riboflavin kinase domain, found primarily in archaea, that catalyses the phosphorylation of riboflavin to form flavin mononucleotide in riboflavin biosynthesis. Its structure resembles a RIFT barrel, structurally similar to but topologically distinct from bacterial and eukaryotic examples []. The N-terminal is a winged helix-turn-helix DNA-binding domain, and the C-terminal half is most similar in sequence to a group of cradle-loop barrels. | Short Name: | Riboflavin_kinase_CTP-dep |
