1.2.1.104: pyruvate dehydrogenase system
This is an abbreviated version!
For detailed information about pyruvate dehydrogenase system, go to the full flat file.
Reaction
Synonyms
aceE, AceF, At1g54220, At3g13930, At3g52200, CTHT_0006350, CTHT_0069820, dihydrolipoamide acetyltransferase, dihydrolipoyllysine-residue acetyltransferase component, DLAT, DLD, DLST, E1 component of pyruvate dehydrogenase complex, E1 component subunit alpha, E1 component subunit beta, IAR4, LpdA, Lta3, MAB1, More, Mrp-3, Pda1, Pda1p, PDC, PDCp, PDH, PDH complex, PDH-E1 catalytic subunit, PDHa, PdhA1, PDHalpha, PdhB1, PDHC, PdhE, PDHE1alpha1, PdhH, PdhX, PH2, plastidial pyruvate dehydrogenase complex, pyruvate decarboxylase, pyruvate dehydrogenase, pyruvate dehydrogenase alpha subunit, pyruvate dehydrogenase complex, pyruvate dehydrogenase E1
ECTree
1.2.1.104 pyruvate dehydrogenase systemAdvanced search results
results (
results (Engineering
Engineering on EC 1.2.1.104 - pyruvate dehydrogenase system
Please wait a moment until all data is loaded. This message will disappear when all data is loaded.
top
PROTEIN VARIANTS 
ORGANISM
UNIPROT
COMMENTARY 
LITERATURE
D15A
variant is neither able to form a complex with the E2 component, nor to produce NADH in the overall assay
D7A
variant is neither able to form a complex with the E2 component, nor to produce NADH in the overall assay
D9A
variant is neither able to form a complex with the E2 component, nor to produce NADH in the overall assay
E12D
variant is neither able to form a complex with the E2 component, nor to produce NADH in the overall assay
E12Q
variant is neither able to form a complex with the E2 component, nor to produce NADH in the overall assay
E401A
mutant displays a modest threefold increase in Km pyruvate, and a significant reduction in kcat/Km pyruvate
H407A
mutation in E1, only modestly affects catalysis through the pyruvate decarboxylation step in isolated E1 (14% activity relative to parental E1), but inhibits the overall complex reaction by three orders of magnitude (0.15% activity compared to parental E1)
I11A
variant is able to form a complex with the E2 component, and produce NADH in the overall assay
I350V/A351V/A358V
PDH activity with the triple mutant at an [NADH]/[NAD+] ratio of 0.15 is higher than that of the wild-type without NADH addition. Within the PDH complex, the mutant is also less sensitive to inhibition by NADH
K403A
mutant displays a modest threefold increase in Km pyruvate, and a significant reduction in kcat/Km pyruvate
N404A
mutation leads to the greatest reduction in overall activity among the alanine-substituted variants and also greatly affects the Kd methyl acetylphosphonate
P10A
variant is able to form a complex with the E2 component, and produce NADH in the overall assay
R14A
variant is neither able to form a complex with the E2 component, nor to produce NADH in the overall assay
T13A
variant is able to form a complex with the E2 component, and produce NADH in the overall assay
Y177A
11% residual pyruvate dehydrogenase multienzyme complex activity, binding of thiamine diphosphate is unaffected
Y177F
7% residual pyruvate dehydrogenase multienzyme complex activity
M131A
-
mutation in the peripheral subunit-binding domain of the E2 chain. Residue M131 makes a significant contribution to the binding of pyruvate decarboxylase E1. Mutation lowers the binding affinity for pyruvate decarboxylase E1 by almost 140fold
R135A
-
mutation in the peripheral subunit-binding domain of the E2 chain, lowers the binding affinity for pyruvate decarboxylase E1 by almost 140fold
R135C
-
mutation in the peripheral subunit-binding domain of the E2 chain, plays an important part in the interaction with both pyruvate decarboxylase E1 and dihydrolipoyl dehydrogenase E3
R156A
-
mutation in the peripheral subunit-binding domain of the E2 chain, lowers the binding affinity for pyruvate decarboxylase E1 by almost 19fold
D289A
-
the mutant does not have any detectable activity in PDC assay while its activity in thedecarboxylation reaction measured by 2,6-dichlorophenolindophenol assay does not significantly change
D289N
-
the mutant does not demonstrate any change in the 2,6-dichlorophenolindophenol assay but its activity is reduced to 67% in PDC assay
D413A
substitutions has no large effects on E3 activity when measured in its free form. However, when reconstituted in the complex, the pyruvate dehydrogenase activity is reduced to 18%. The binding affinities of the mutant to the the di-domain of the E3-binding protein are severely reduced
E229A
-
the mutant does not show any significant changes compared with the wild type subunit E1 activity
E229Q
-
the mutant does not show any significant changes compared with the wild type subunit E1 activity
E232A
-
the mutant does not show any significant changes compared with the wild type subunit E1 activity
E232Q
-
the mutant does not show any significant changes compared with the wild type subunit E1 activity
E234A
-
the mutant does not show any significant changes compared with the wild type subunit E1 activity
E234Q
-
the mutant does not show any significant changes compared with the wild type subunit E1 activity
H63A
-
about 17% residual activity in assay using 2,6-dichlorophenolindophenol, only modest inhibition by acetylphosphinate and acetylmethylphosphinate
I329A
-
the mutant shows reductions in activities in both the 2,6-dichlorophenolindophenol and PDC assays
I329del
-
the mutant shows reductions in activities in both the 2,6-dichlorophenolindophenol and PDC assays
M153V
-
the mutant shows decreased PDH activity in fibroblasts, around 30% of mean control
Q206L
-
the mutant shows decreased PDH activity in fibroblasts, around 52% of mean control
S203A/S64A
-
phosphorylation at remaining site S271 causes complete inactivation
Y438A
substitutions has no large effects on E3 activity when measured in its free form. However, when reconstituted in the complex, the pyruvate dehydrogenase activity is reduced to 9%. The binding affinities of the mutant to the the di-domain of the E3-binding protein are severely reduced and binding of is accompanied by an unfavorable enthalpy change and a large positive entropy change
Y438H
substitutions has no large effects on E3 activity when measured in its free form. However, when reconstituted in the complex, the pyruvate dehydrogenase activity is reduced to 20%. The binding affinities of the mutant to the the di-domain of the E3-binding protein are severely reduced
additional information
additional information
construction of a cysteine-less variant of the E1 component, onto which cysteines are substituted at selected loop positions. In the absence of ligand, the loop exists in two conformations, and the rate constant for loop movement is of the same order of magnitude as the turnover number for the enzyme under the same conditions
additional information
construction of deletion mutants of the E1 pyruvate dehydrogenase component lacking amino acids 6-15, 16-25, 26-35, 36-45, and 46-55, along with single-site substitutions at Asp7, Asp9, Pro10, Ile11, Glu12, Thr13, Arg14, and Asp15. The decarboxylation of pyruvate and the ability of PDHc-E1 to dimerize are not affected by any of the deletions or substitutions. Deletion mutant 46-55 and the Pro10Ala, Ile11Ala, and Thr13Ala variants are able to form a complex with the E2 component, and produce NADH in the overall assay, deletion mutants 16-25, 26-35, and 36-45 and the Asp7Ala, Asp9Ala, Glu12Gln, Glu12Asp, Arg14Ala, and Asp15Ala variants fail in both. All constructs can carry out reductive acetylation of the Escherichia coli lipoyl domain and reductively acetylate the Escherichia coli E2 component
additional information
mutation of a prominent surface loop that links the first and second beta-strands in all lipoyl domains, of E2 dihydrolipoyl acetyltransferase. Deletion of the loop (four residues) renders the domain incapable of reductive acetylation by pyruvate dehydrogenase complex subunit E1p in the presence of pyruvate. Additional exchange of the two residues on the C-terminal side of the loop (V14A, E15T) has no effect. Exchanging the residue on the N-terminal side of the lipoyl-lysine beta-turn in the E2p and E2o domains (G39T), both singly and in conjunction with the loop exchange, has no effect on the ability of the E2p domain to be reductively acetylated but does confer a slight increase in susceptibility to reductive succinylation. All mutant E2p domains, apart from that with the loop deletion, are readily lipoylated in vitro by lipoate protein ligase A
additional information
-
mutational analysis of key amino acid residues responsible for enzyme component assembly to the multienzyme complex using E3 component mutants, overview
additional information
-
residues K136, K153, R146, S133 do not contribute to the interaction with pyruvate decarboxylase E1
additional information
-
the in-frame deletion mutant G143del and the 65 bp duplication mutant c.900-6_958dup65 show decreased PDH activity in fibroblasts, around 16% of mean control
