| Type: | Domain | Name: | Glutamine synthetase/guanido kinase, catalytic domain |
| Description: | The C-terminal catalytic domains of glutamine synthetase and the guanido kinase family (which includes creatine kinase and arginine kinase) share a common structural fold, namely a common core consisting of two beta-alpha-beta2-alpha repeats [].Glutamine synthetase () (GS) [] plays an essential role in the metabolism of nitrogen by catalysing the condensation of glutamate and ammonia to form glutamine. There seem to be three different classes of GS [, , ]. Class I enzymes (GSI) are specific to prokaryotes, and are oligomers of 12 identical subunits; the activity of GSI-type enzyme is controlled by the adenylation of a tyrosine residue. Class II enzymes (GSII) are found in eukaryotes and in bacteria, and are oligomers of 8 identical subunits. Class III enzymes (GSIII) have been found in Bacteroides fragilisin Butyrivibrio fibrisolvens, and are oligomers of six identical subunits. While the three classes of GS's are clearly structurally related, the sequence similarities are not so extensive.ATP:guanido phosphotransferases are a family of structurally and functionally related enzymes [, ] that reversibly catalyse the transfer of phosphate between ATP and various phosphogens. The enzymes belonging to this family include:Glycocyamine kinase (), which catalyses the transfer of phosphate from ATP to guanidoacetate.Arginine kinase (), which catalyses the transfer of phosphate from ATP to arginine.Taurocyamine kinase (), an annelid-specific enzyme that catalyses the transfer of phosphate from ATP to taurocyamine.Lombricine kinase (), an annelid-specific enzyme that catalyses the transfer of phosphate from ATP to lombricine.Smc74, a cercaria-specific enzyme from Schistosoma mansoni[].Creatine kinase () (CK) [, ], which plays an important role in energy metabolism of vertebrates. | Short Name: | Gln_synth/guanido_kin_cat_dom |
