Biosynthesis of lysine in plants: the putative role of meso-diaminopimelate dehydrogenase.
Extracts from Chlamydomonas, corn, soybean and tobacco were tested for enzymes of the lysine biosynthetic pathway. Dihydrodipicolinic acid (DHD) synthase, DHD reductase, diaminopimelate (DAP) epimerase and DAP decarboxylase were present in all. However, in contrast to the report of Wenko et al., meso-DAP dehydrogenase could not be detected in extracts prepared from soybean. Moreover, it was not found in Chlamydomonas, corn and tobacco as well. In order to set an upper limit to the amount of meso-DAP dehydrogenase that might be present, reconstruction experiments were performed with soybean and corn extracts in which the conversion of dihydrodipicolinate to lysine was made dependent on the addition of limited amounts of the meso-DAP dehydrogenase purified from Bacillus sphaericus. The presence of DAP epimerase and the absence of meso-DAP dehydrogenase indicates that the meso-DAP dehydrogenase abbreviated pathway for lysine synthesis is not operative in plants.
Chatterjee
S P
SP
Department of Molecular Biology, Princeton University, NJ 08544.
Singh
B K
BK
Gilvarg
C
C
D000591:Amino Acid Isomerases; D000594:Amino Acid Oxidoreductases / Q000378:metabolism*; D000818:Animals; D001426:Bacterial Proteins; D002262:Carboxy-Lyases / Q000378:metabolism; D016825:Chlamydomonas reinhardtii / Q000201:enzymology*; D050746:Dihydrodipicolinate Reductase; D006836:Hydro-Lyases / Q000378:metabolism; D006863:Hydrogen-Ion Concentration; D008239:Lysine / Q000096:biosynthesis*; D010088:Oxidoreductases / Q000378:metabolism; D044925:Oxidoreductases Acting on CH-CH Group Donors; D010944:Plants / Q000201:enzymology*; D010947:Plants, Toxic; D019998:Racemases and Epimerases / Q000378:metabolism; D013025:Glycine max / Q000201:enzymology; D013045:Species Specificity; D014026:Nicotiana / Q000201:enzymology; D003313:Zea mays / Q000201:enzymology
D001426:Bacterial Proteins; D010088:Oxidoreductases; D050746:Dihydrodipicolinate Reductase; D044925:Oxidoreductases Acting on CH-CH Group Donors; D000594:Amino Acid Oxidoreductases; C020032:diaminopimelate dehydrogenase; D002262:Carboxy-Lyases; C079912:LysA protein, Bacteria; C020031:diaminopimelic acid decarboxylase; D006836:Hydro-Lyases; C020040:4-hydroxy-tetrahydrodipicolinate synthase; D019998:Racemases and Epimerases; D000591:Amino Acid Isomerases; C042032:diaminopimelate epimerase; D008239:Lysine