2.3.1.240: narbonolide synthase
This is an abbreviated version!
For detailed information about narbonolide synthase, go to the full flat file.
Reaction
Synonyms
methymycin/picromycin polyketide synthase, picromycin/methymycin PKS, picromycin/methymycin polyketide synthase, PICS, PikAI, PikAIII, PikAIV, pikromycin PKS, pikromycin polyketide synthase, type I polyketide synthase PikAIV
ECTree
2.3.1.240 narbonolide synthaseAdvanced search results
results (
results (KM Value
KM Value on EC 2.3.1.240 - narbonolide synthase
Please wait a moment until all data is loaded. This message will disappear when all data is loaded.
top
KM VALUE [mM] 
SUBSTRATE
ORGANISM
UNIPROT
COMMENTARY 
LITERATURE
IMAGE
0.41
(E)-(2S,4R,8R,9R)-S-2-acetamidoethyl 9-hydroxy-2,4,8-trimethyl-5-oxoundec-6-enethioate
pH 7.2, 30°C, Km-valkue for activity with the polyketide synthase PikAIII/polyketide synthase PikAIV complex in formation of narbonolide
additional information
additional information
both PikAIV(DELTAAT) and PikAIV(DELTAACP) display similar apparent kcat values for 10-deoxymethynolide production, which are approximately 2fold lower than the calculated kcat from wild-type PikAIII and PikAIV. Likewise, both PikAIV mutants display similar apparent KM values that are also reduced 2fold when compared to the KM from PikAIII and PikAIV. The equivalent decrease in the apparent kinetic parameters for both mutants results in a specificity constant (kcat/KM) that is comparable to wild-type, further emphasizing the non-critical role of these catalytic domains in 10-deoxymethynolide production. Both PikAIII(DELTADock) (partial deletions of PikAIII C-terminal domain) and PikAIV(DELTADock) (partial deletion of PikAIV N-terminal docking domains) display apparent kcat values (0.044/min and 0.053/min), which are significantly decrease relative to the kcat observed with wild-type PikAIII and PikAIV. The apparent KM values for PikAIII(DELTADock) and PikAIV (DELTADock) decrease 35 fold compared to wild-type, resulting in specificity constants (kcat/KM) that are 14fold and 8fold lower, respectively. Combining PikAIII(DELTADock) and PikAIV(DELTADock) together do not result in an additional rate decrease. The kinetic parameters are comparable to those obtained when either truncated monomodule is paired with its wild-type partner
-
