Functional analysis of aromatic biosynthetic pathways in Pseudomonas putida KT2440.
Bottom Line: Genes for tryptophan biosynthesis are grouped in unlinked regions with the trpBA and trpGDE genes organized as operons and the trpI, trpE and trpF genes organized as single transcriptional units.The pheA and tyrA gene-encoding multifunctional enzymes for phenylalanine and tyrosine biosynthesis are linked in the chromosome and form an operon with the serC gene involved in serine biosynthesis.The last step in the biosynthesis of these two amino acids requires an amino transferase activity for which multiple tyrB-like genes are present in the host chromosome.
Affiliation: Consejo Superior de Investigaciones Científicas, Estación del Zaidín, Department of Environmental Protection, Granada, Spain.Show MeSH
Related in: MedlinePlus
Mentions: Physical analysis of the ORF PP1769/PP1770 region revealed that ORF PP1769 overlapped with the preceding gene annotated as serC by six nucleotides, and was separated from ORF PP1770 by 61 nucleotides (Fig. 4). As the two ORFs identified as involved in phenylalanine/tyrosine biosynthesis were adjacent, we used RT‐PCR and found that pheA forms an operon with the preceding serC gene and also with PP1770, which encodes the TyrA prephenate dehydrogenase. All three genes are transcribed as part of the same operon. These three genes are also co‐transcribed with cmK and rpsA, located downstream of tyrA, but not with gyrA located upstream of serC (not shown). A supraoperon organization of the serC/pheA/tyrA genes was also found in P. stutzeri (Xie et al., 1999).
Affiliation: Consejo Superior de Investigaciones Científicas, Estación del Zaidín, Department of Environmental Protection, Granada, Spain.