Prenyltransferases catalyze the polymerization condensation reaction of isopentenyl diphosphate (IPP) and allylic acceptors of varying lengths. Throughout the prenyltransferases enzymes found in the family, Actinobacteria, there exist two catalytic DDxxD motifs in the amino acid sequence. The 4th and 5th amino acid residues before the first motif classically determine chain length of the isoprenoid product and, through manipulation of those amino acids, the resulting chain length can be altered based on the size of the amino acid residue. Corynebacterium glutamicum contains the conserved DDxxD motifs, but the upstream amino acids vary across the three predicted prenyltransferases. Additionally, the presence of a third prenyltransferase is uncommon in the genus. The goal of the project is to explore the naturally occurring variation encoded in the C. glutamicum genome. The one specific, well-conserved gene in C. glutamicum was cloned and manipulated using site-directed mutagenesis to model the paralogs. The mutant sequences were confirmed, and recombinantly expressed in Escherichia coli for the determination of the isoprenoid product, compared to the wild-type’s 20-carbon chain product, geranylgeranyl pyrophosphate, or GGPP.
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