Flux through the tetrahydrodipicolinate succinylase pathway is dispensable for L-lysine production in Corynebacterium glutamicum.
The N-succinyl-LL-diaminopimelate desuccinylase gene (dapE) in the four-step succinylase branch of the L-lysine biosynthetic pathway of Corynebacterium glutamicum was disrupted via marker-exchange mutagenesis to create a mutant strain that uses only the one-step meso-diaminopimelate dehydrogenase branch to overproduce lysine. This mutant strain grew and utilized glucose from minimal medium at the same rate as the parental strain. In addition, the dapE- strain produced lysine at the same rate as its parent strain. Transformation of the parental and dapE- strains with the amplified meso-diaminopimelate dehydrogenase gene (ddh) on a plasmid did not affect lysine production in either strain, despite an eightfold amplification of the activity of the enzyme. These results indicate that the four-step succinylase pathway is dispensable for lysine overproduction in shake-flask culture. In addition, the one-step meso-diaminopimelate dehydrogenase pathway does not limit lysine flux in Corynebacterium under these conditions.
Shaw-Reid
C A
CA
Department of Chemical Engineering, Massachusetts Institute of Technology, Cambridge 02139, USA.
McCormick
M M
MM
Sinskey
A J
AJ
Stephanopoulos
G
G
D000217:Acyltransferases / Q000235:genetics / Q000378:metabolism*; D000581:Amidohydrolases / Q000235:genetics* / Q000502:physiology; D000594:Amino Acid Oxidoreductases / Q000235:genetics / Q000378:metabolism; D003352:Corynebacterium / Q000235:genetics / Q000254:growth & development / Q000378:metabolism*; D005947:Glucose / Q000378:metabolism; D008239:Lysine / Q000096:biosynthesis*; D016296:Mutagenesis; D013997:Time Factors; D014169:Transformation, Bacterial / Q000235:genetics
D000217:Acyltransferases; D000581:Amidohydrolases; D000594:Amino Acid Oxidoreductases; D005947:Glucose; D008239:Lysine; C020032:diaminopimelate dehydrogenase; C040777:succinyl-CoA-tetrahydrodipicolinate N-succinyltransferase; C054685:N-succinyl-l,l-diaminopimelic acid desuccinylase