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The two reactions compared are done so using a Tanimoto similarity score (for more information, please see the MACiE FAQ) for the bond changes only. The score maay range from 0 to 1 where 1 indicates that the two reactions are identical at the bond change level and 0 indicates that there are no bond changes in common.


Key

1.0-0.9 0.9-0.8 0.8-0.7 0.7-0.6 0.6-0.5 0.5-0.4 0.4-0.3 0.3-0.2 0.2-0.1 0.1-0.0 =0

Results for Comparison of M0237 and M0188

These two reactions have a combined similarity of 0.41


M0237

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Comparison

M0188

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EC 1.5.1.33
pteridine reductase
Class EC 5.1.3.2
UDP-glucose 4-epimerase

Image of NADPH

Image of Biopterin

Image of Proton

right arrow

Image of NADP+

Image of Tetrahydrobiopterin

2 NADPH
C00005
CHEBI:16474
Biopterin
C06313
CHEBI:15373
2 Proton
C00080
CHEBI:24636
2 NADP+
C00006
CHEBI:18009
Tetrahydrobiopterin
C00272
CHEBI:52447
0

Image of UDP-galactose

right arrow

Image of UDP-glucose

UDP-galactose
C00052
CHEBI:58439
UDP-glucose
C00029
CHEBI:58367

Catalytic CATH Codes

3.40.50.720

Catalytic CATH Codes

3.40.50.720

Active Site



0.2229

Active Site



Catalytic Residues

Type Number Chain Location of Function
Arg 14 A Side Chain
Asp 161 A Side Chain
Tyr 174 A Side Chain
0.2

Catalytic Residues

Type Number Chain Location of Function
Ser 124 A Side Chain
Tyr 149 A Side Chain
Lys 153 A Side Chain

Organic Cofactors

No Associated Organic Cofactors

Organic Cofactors

Type Identity Chain
NAD NAD 340

Metal Cofactors

No Associated Metal Cofactors

Metal Cofactors

No Associated Metal Cofactors

Reaction occurs across 3 steps

0.5555

Reaction occurs across 2 steps

Step 1
GIF of Reaction Step M0237.stg01

NADPH transfers a hydride to the C7 position of biopterin. The N8 position is protonated by Tyr174, which in turn is protonated by Asp161. Since Asp161 is exposed to the bulk solvent it is then protonated by water.
0.57 Step 1
GIF of Reaction Step M0188.stg01

Tyr149 deprotonates the 4-hydroxide of the substrate, resulting in an elimination of the hydride from the C4 position. The hydride then attacks the NAD cofactor in a nucleophilic addition reaction.
Step 2
GIF of Reaction Step M0237.stg02

The dihydrobiopterin intermediate tautomerises.
0.5 Step 2
GIF of Reaction Step M0188.stg02

The intermediate undergoes a conformational change before the NAD initiates an elimination of the hydride back to the intermediate, which in turn deprotonates Tyr149.
Step 3
GIF of Reaction Step M0237.stg03

NADPH transfers a hydride to the C6 position of the dihydrobiopterin intermediate. The N5 position is protonated by an activated water. This water then deprotonates the 4-hydroxyl group and causes tautomerisation back to the keto-form.
N/A Step 3
No Step with this number present

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