6.3.4.2 - 6.3.4.2 a carboxyl-terminal FLAG sequence is introduced after insertion of human CTPS1 into pCDNA 4 myc/his, expression by transient transfection of human embryonic kidney (HEK) 293 cells 6.3.4.2 cDNA encoding the synthetase domain of human CTPS (isoform 1) is subcloned into the pNIC-Bsa4 vector, the resulting construct codes for a protein with an N-terminal hexahistidine tag with an integrated TEV protease-cleavage site, the entire plasmid is transformed in Escherichia coli BL-21 6.3.4.2 cloned in Escherichia coli as a histidine-tagged fusion protein 6.3.4.2 cloned in Escherichia coli BL-21 as an N-terminal 6xHis-tag fusion protein 6.3.4.2 expressed in Escherichia coli BL21(DE3) cells 6.3.4.2 expression in a ura7ura8 double mutant that lacks CTP synthetase activity 6.3.4.2 expression in Escherichia coli 6.3.4.2 expression of the human type II CTP synthetase gene in the CTP synthetase-deficient mutant Escherichia coli JF618 completely abolishes the need for exogenous cytidine for their survival 6.3.4.2 expression of the mutant enzyme D149E in Escherichia coli 6.3.4.2 expression of wild-type and mutant enzymes in HEK-293 cells, co-expression with GST-tagged Xenopus laevis peptidyl prolyl isomerase Pin1 6.3.4.2 functional expression of human CTPS1 and CTPS2 genes that encode CTP synthetase enzymes in enzyme-deficient Saccharomyces cerevisiae ura7D/ura8D double mutant, complementation 6.3.4.2 genes ura7D and ura8D, DNA and amino acid sequence determination and analysis, expression analysis 6.3.4.2 human CTP synthetase 1 is expressed and purified from a Saccharomyces cerevisiae ura7delta ura8delta double mutant that lacks CTP synthetase activity 6.3.4.2 overexpression as a hexahistidine-tagged form 6.3.4.2 protein is expressed as a His6-tagged wild type human CTP synthetase 1 fusion protein in Escherichia coli 6.3.4.2 protein is expressed as a His6-tagged wild type human CTP synthetase 1 fusion protein in Saccharomyces cerevisiae 6.3.4.2 synthetase-His6-TEV protease site-tagged Trypanosoma brucei CTP synthetase is expressed in BL21(DE3) pLysS bacteria 6.3.4.2 wild-type and L109A recombinant enzyme are expressed in Escherichia coli BL21(DE3)