| abstract |
Aspects of the disclosure relate to biosynthesis of histidine in host cells. For example, host cells may comprise: a promoter; a ribosome binding site (RBS); and a nucleic acid comprising: hisG; hisD; hisC\ hisB; hisH; hisA; hisF; and/or hisl. Host cells may further comprise a nucleic acid encoding a ribose phosphate pyrophosphokinase (RPPK), optionally comprising one or more amino acid substitutions relative to the sequence of wildtype E. coli RPPK. Host cells of the disclosure may comprise a nucleic acid encoding a 5,10-methylene-tetrahydrofolate dehydrogenase/ 5,10-methylene-tetrahydrofolate cyclohydrolase (MTHFDC) enzyme. Further aspects of the disclosure relate to production of purine pathway metabolites and/or plasmid DNA in host cells. |