Gene/Protein
Disease
Symptom
Drug
Enzyme
Compound
Pivot Concepts:
Gene/Protein
Disease
Symptom
Drug
Enzyme
Compound
Target Concepts:
Gene/Protein
Disease
Symptom
Drug
Enzyme
Compound
Query: DrugBank:EXPT02288 (
NADH
)
21,914
document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)
D-Glucuronic acid is a biomass component that occurs in plant cell wall polysaccharides and is catabolized by saprotrophic microorganisms including fungi. A pathway for D-glucuronic acid catabolism in fungal microorganisms is only partly known. In the filamentous fungus
Aspergillus niger
, the enzymes that are known to be part of the pathway are the NADPH requiring D-glucuronic acid reductase forming L-gulonate and the
NADH
requiring 2-keto-L-gulonate reductase that forms L-idonate. With the aid of RNA sequencing we identified two more enzymes of the pathway. The first is a NADPH requiring 2-keto-L-gulonate reductase that forms L-idonate, GluD. The second is a NAD
+
requiring
L-idonate 5-dehydrogenase
forming 5-keto-gluconate, GluE. The genes coding for these two enzymes are clustered and share the same bidirectional promoter. The GluD is an enzyme with a strict requirement for NADP
+
/NADPH as cofactors. The k
cat
for 2-keto-L-gulonate and L-idonate is 21.4 and 1.1 s
-1
, and the K
m
25.3 and 12.6 mM, respectively, when using the purified protein. In contrast, the GluE has a strict requirement for NAD
+
/
NADH
. The k
cat
for L-idonate and 5-keto-D-gluconate is 5.5 and 7.2 s
-1
, and the K
m
30.9 and 8.4 mM, respectively. These values also refer to the purified protein. The
gluD
deletion resulted in accumulation of 2-keto-L-gulonate in the liquid cultivation while the
gluE
deletion resulted in reduced growth and cessation of the D-glucuronic acid catabolism.
...
PMID:Clustered Genes Encoding 2-Keto-l-Gulonate Reductase and l-Idonate 5-Dehydrogenase in the Novel Fungal d-Glucuronic Acid Pathway. 2826 Nov 81
