title: Biosynthesis of lysine in plants: evidence for a variant of the known bacterial pathways.
abstract: With the aim of elucidating how plants synthesize lysine, extracts prepared from corn, tobacco, Chlamydomonas and soybean were tested and found to lack detectable amounts of N-alpha-acyl-L,L-diaminopimelate deacylase or N-succinyl-alpha-amino-epsilon-ketopimelate-glutamate aminotransaminase, two key enzymes in the central part of the bacterial pathway for lysine biosynthesis. Corn extracts missing two key enzymes still carried out the overall synthesis of lysine when provided with dihydrodipicolinate. An analysis of available plant DNA sequences was performed to test the veracity of the negative biochemical findings. Orthologs of dihydrodipicolinate reductase and diaminopimelate epimerase (enzymes on each side of the central pathway) were readily found in the Arabidopsis thaliana genome. Orthologs of the known enzymes needed to convert tetrahydrodipicolinate to diaminopimelic acid (DAP) were not detected in Arabidopsis or in the plant DNA sequence databases. The biochemical and reinforcing bioinformatics results provide evidence that plants may use a novel variant of the bacterial pathways for lysine biosynthesis.
authors.affiliation: Biotech Center and Department of Plant Biology and Pathology, Rutgers University, 59 Dudley Road, New Brunswick, NJ 08901-8520, USA.
authors.forename: Andre' O
authors.initials: AO
authors.lastname: Hudson
authors.forename: Christine
authors.initials: C
authors.lastname: Bless
authors.forename: Polliana
authors.initials: P
authors.lastname: Macedo
authors.forename: Siba P
authors.initials: SP
authors.lastname: Chatterjee
authors.forename: Bijay K
authors.initials: BK
authors.lastname: Singh
authors.forename: Charles
authors.initials: C
authors.lastname: Gilvarg
authors.forename: Thomas
authors.initials: T
authors.lastname: Leustek
mesh_terms: D001419:Bacteria / Q000378:metabolism*; D002262:Carboxy-Lyases / Q000378:metabolism; D003960:Diaminopimelic Acid / Q000378:metabolism; D050746:Dihydrodipicolinate Reductase; D029968:Escherichia coli Proteins / Q000378:metabolism; D008239:Lysine / Q000096:biosynthesis*; D044925:Oxidoreductases Acting on CH-CH Group Donors / Q000378:metabolism; D010802:Phylogeny; D010944:Plants / Q000378:metabolism*
chemical_list: D029968:Escherichia coli Proteins; D003960:Diaminopimelic Acid; D050746:Dihydrodipicolinate Reductase; D044925:Oxidoreductases Acting on CH-CH Group Donors; D002262:Carboxy-Lyases; C489812:LysA protein, E coli; D008239:Lysine