Biosynthetic Pathways. III. The Biosynthesis of Lysine by Torulopsis utilis¹

Wild‐Type and Mutant Forms of Homoisocitric Dehydrogenase in the Yeast Saccharomycopsis lipolytica

“…The conversion of homoisocitric acid (1-hydroxy-l,2,4-butanetricarboxylic acid) into 2-oxoadipic, a precursor of lysine biosynthesis in yeast was first proposed on the basis of isotopic tracer experiments [ 1,2]. An enzyme fraction, termed homoisocitric dehydrogenase was purified 500-fold by Rowley and Tucci [3] from Saccharornyces cerevisiae and shown to catalyze the oxidative decarboxylation of homoisocitric acid.…”

Crystal Structure of the LysY·LysW Complex from Thermus thermophilus

“…We previously reported that the hyperthermophilic bacterium, Thermus thermophilus, biosynthesizes lysine from 2-oxoglutarate via ␣-aminoadipate (AAA) 2 as an intermediate (2). The first half of this pathway (3-6) is similar to the fungal AAA pathway (7,8), whereas the latter half utilizes the small acidic protein LysW to protect the ␣-amino group of AAA (9), unlike the fungal AAA pathway. LysX catalyzes the formation of an isopeptide bond between the C-terminal Glu of LysW and the ␣-amino group of AAA, and the resulting LysW-␥-AAA is further converted into LysW-␥-lysine through sequential reactions catalyzed by LysZ, LysY, and LysJ, which show homology to the arginine biosynthetic enzymes, ArgB, ArgC, and ArgD, respectively (10).…”

Structural Insight into Amino Group-carrier Protein-mediated Lysine Biosynthesis

“…Bacteria and plants generally produce lysine through the diaminopimelate pathway starting from aspartate (1), whereas fungi and yeast biosynthesize lysine via ␣-aminoadipate (AAA) 2 (2,3). Although Thermus thermophilus is an extremely thermophilic bacterium, lysine is synthesized using AAA as an intermediate (4).…”