Information on EC 5.3.1.12 - Glucuronate isomerase

New: Word Map on EC 5.3.1.12
Please wait a moment until all data is loaded. This message will disappear when all data is loaded.
Specify your search results
Mark a special word or phrase in this record:
Select one or more organisms in this record:
Show additional data
Do not include text mining results
Include (text mining) results (more...)
Include results (AMENDA + additional results, but less precise; more...)


The expected taxonomic range for this enzyme is: Bacteria

EC NUMBER
COMMENTARY
5.3.1.12
-
RECOMMENDED NAME
GeneOntology No.
Glucuronate isomerase
REACTION
REACTION DIAGRAM
COMMENTARY
ORGANISM
UNIPROT
LITERATURE
D-Glucuronate = D-fructuronate
show the reaction diagram
-
-
-
-
D-Glucuronate = D-fructuronate
show the reaction diagram
reaction mechanism, overview
-
D-Glucuronate = D-fructuronate
show the reaction diagram
reaction mechanism, overview
C6EHQ2
D-Glucuronate = D-fructuronate
show the reaction diagram
reaction mechanisms in which an active site base abstracts the proton from C2 of D-glucuronate to form a cisenediol intermediate. The conjugate acid then transfers this proton to C1 of the cis-enediol intermediate to form D-fructuronate
P0A8G3
REACTION TYPE
ORGANISM
UNIPROT
COMMENTARY
LITERATURE
isomerization
-
-
-
-
PATHWAY
BRENDA Link
KEGG Link
MetaCyc Link
beta-D-glucuronide and D-glucuronate degradation
-
-
D-galacturonate degradation I
-
-
degradation of sugar acids
-
-
Metabolic pathways
-
-
pectin degradation III
-
-
Pentose and glucuronate interconversions
-
-
SYSTEMATIC NAME
IUBMB Comments
D-glucuronate aldose-ketose-isomerase
Also converts D-galacturonate to D-tagaturonate.
SYNONYMS
ORGANISM
UNIPROT
COMMENTARY
LITERATURE
D-Glucuronate isomerase
-
-
-
-
D-glucuronate ketol-isomerase
-
-
-
-
Glucuronate isomerase
-
-
-
-
Isomerase, glucuronate
-
-
-
-
Uronate isomerase
-
-
-
-
Uronic isomerase
-
-
-
-
CAS REGISTRY NUMBER
COMMENTARY
9023-87-4
-
ORGANISM
COMMENTARY
LITERATURE
UNIPROT
SEQUENCE DB
SOURCE
gene uxaC
UniProt
Manually annotated by BRENDA team
strain K-12, wild type and mutant strains
-
-
Manually annotated by BRENDA team
SUBSTRATE
PRODUCT                      
REACTION DIAGRAM
ORGANISM
UNIPROT
COMMENTARY
(Substrate)
LITERATURE
(Substrate)
COMMENTARY
(Product)
LITERATURE
(Product)
Reversibility
r=reversible
ir=irreversible
?=not specified
D-Fructuronate
?
show the reaction diagram
-
first step in the pathway of glucuronic acid metabolism and galacturonic acid metabolism
-
-
-
D-Galacturonate
D-Tagaturonate
show the reaction diagram
-
-
-
-
-
D-Galacturonate
D-Tagaturonate
show the reaction diagram
-
-
-
-
D-Galacturonate
D-Tagaturonate
show the reaction diagram
-
-
-
-
?
D-Galacturonate
D-Tagaturonate
show the reaction diagram
-
-
-
-
r
D-Galacturonate
D-Tagaturonate
show the reaction diagram
C6EHQ2
-
-
-
r
D-Galacturonate
D-Tagaturonate
show the reaction diagram
-
r
-
-
-
D-Galacturonate
D-Tagaturonate
show the reaction diagram
-
r
-
-
-
D-Galacturonate
?
show the reaction diagram
-
first step in the pathway of glucuronic acid metabolism and galacturonic acid metabolism
-
-
-
D-Glucuronate
D-Fructuronate
show the reaction diagram
-
-
-
-
-
D-Glucuronate
D-Fructuronate
show the reaction diagram
-
-
-
-
?
D-Glucuronate
D-Fructuronate
show the reaction diagram
-
-
-
-
D-Glucuronate
D-Fructuronate
show the reaction diagram
-
-
-
-
-
D-Glucuronate
D-Fructuronate
show the reaction diagram
-
-
-
-
?
D-Glucuronate
D-Fructuronate
show the reaction diagram
-
-
-
-
r
D-Glucuronate
D-Fructuronate
show the reaction diagram
P0A8G3
-
-
-
?
D-Glucuronate
D-Fructuronate
show the reaction diagram
C6EHQ2
-
-
-
r
D-Glucuronate
D-Fructuronate
show the reaction diagram
-
the mononuclear metal center in the active site is ligated to the C6 carboxylate and the C5 hydroxyl group of the substrate, this hydroxyl group is also hydrogen-bonded to Asp355. The C2 and C3 hydroxyl groups of the substrate are hydrogen bonded to Arg357 and the carbonyl group at C1 is hydrogen bonded to Tyr50
-
-
r
D-Glucuronate
?
show the reaction diagram
-
first step in the pathway of glucuronic acid metabolism and galacturonic acid metabolism
-
-
-
D-Tagaturonate
?
show the reaction diagram
-
first step in the pathway of glucuronic acid metabolism and galacturonic acid metabolism
-
-
-
additional information
?
-
-
the enzyme does not participate in the metabolism of heparin or chondroitin sulfate
-
-
-
additional information
?
-
-
active site structure and molecular reaction mechanism, proton transfer from C2 of D-glucuronate to C1 that is initiated by the combined actions of Asp-355 from the end of ?-strand 8 and the C-5 hydroxyl of the substrate that is bound to the metal ion. Formation of the proposed cis-enediol intermediate is further facilitated by the shuttling of the proton between the C2 and C1 oxygens by the conserved Tyr50 and/or Arg355
-
-
-
additional information
?
-
C6EHQ2
chemical mechanism and active site structure, mutational analysis, overview
-
-
-
NATURAL SUBSTRATES
NATURAL PRODUCTS
REACTION DIAGRAM
ORGANISM
UNIPROT
COMMENTARY
(Substrate)
LITERATURE
(Substrate)
COMMENTARY
(Product)
LITERATURE
(Product)
REVERSIBILITY
r=reversible
ir=irreversible
?=not specified
D-Fructuronate
?
show the reaction diagram
-
first step in the pathway of glucuronic acid metabolism and galacturonic acid metabolism
-
-
-
D-Galacturonate
D-Tagaturonate
show the reaction diagram
-
-
-
-
r
D-Galacturonate
D-Tagaturonate
show the reaction diagram
C6EHQ2
-
-
-
r
D-Galacturonate
?
show the reaction diagram
-
first step in the pathway of glucuronic acid metabolism and galacturonic acid metabolism
-
-
-
D-Glucuronate
D-Fructuronate
show the reaction diagram
-
-
-
-
r
D-Glucuronate
D-Fructuronate
show the reaction diagram
C6EHQ2
-
-
-
r
D-Glucuronate
?
show the reaction diagram
-
first step in the pathway of glucuronic acid metabolism and galacturonic acid metabolism
-
-
-
D-Tagaturonate
?
show the reaction diagram
-
first step in the pathway of glucuronic acid metabolism and galacturonic acid metabolism
-
-
-
additional information
?
-
-
the enzyme does not participate in the metabolism of heparin or chondroitin sulfate
-
-
-
COFACTOR
ORGANISM
UNIPROT
COMMENTARY
LITERATURE
IMAGE
FAD
P0A8G3
-
NADH
-
required
NADH
C6EHQ2
required
METALS and IONS
ORGANISM
UNIPROT
COMMENTARY
LITERATURE
Co2+
-
stimulation is more potent at lower concentrations than stimulation by Mn2+
Mn2+
-
maximal stimulation is higher than stimulatipn by Zn2+ or Co2+, stimulation at low concentrations is lower than stimulation by Zn2+ and Co2+
Zn2+
-
stimulation is more potent at lower concentrations than stimulation by Mn2+. Vmax is about 3times higher in presence of 0.1 mM Mn2+ than in presence of 0.01 mM Zn2+ or Co2+
Zn2+
P0A8G3
enzyme contains 1 equiv of zinc per subunit
Zn2+
-
contains 0.5 equivalents of Zn2+ per subunit
Zn2+
C6EHQ2
URI contains up to 1 equivalent
INHIBITORS
ORGANISM
UNIPROT
COMMENTARY
LITERATURE
IMAGE
(2S,3R,4S)-4-(hydroxycarbamoyl)-2,3,4-trihydroxybutanoate
-
-
1,10-phenanthroline
-
-
2,2'-dipyridyl
-
-
2-mercaptoethanol
-
-
arabinohydroxamate
-
-
cysteine
-
-
D-arabinarate
-
-
D-arabinaric acid
P0A8G3
competitive inhibitor
D-arabinaric acid
-
-
D-arabinohydroxamate
P0A8G3
competitive inhibitor
EDTA
-
0.25 mM, 50% inhibition
glutathione
-
weak
L-Gulonic acid
P0A8G3
competitive inhibitor
KM VALUE [mM]
SUBSTRATE
ORGANISM
UNIPROT
COMMENTARY
LITERATURE
IMAGE
0.05
D-galacturonate
-
at 30C, pH 8.0
0.8
D-galacturonate
-
strain Hfr P4X
1.65
D-galacturonate
-
-
0.05
D-glucuronate
-
at 30C, pH 8.0
0.05
D-glucuronate
C6EHQ2
pH 8.0, 25C, mutant H33N
0.16
D-glucuronate
C6EHQ2
pH 8.0, 25C, mutant Y60F
0.2
D-glucuronate
C6EHQ2
pH 8.0, 25C, mutant H33A
0.29
D-glucuronate
-
in absence of added metal or chelator
0.3
D-glucuronate
P0A8G3
reconstituted with Co2+, 30C, pH 8
0.31
D-glucuronate
-
in presence of 0.01 mM Zn2+
0.4
D-glucuronate
C6EHQ2
pH 8.0, 25C, mutant D412A
0.41
D-glucuronate
-
in presence of 0.01 mM Co2+
0.48
D-glucuronate
P0A8G3
reconstituted with Mn2+, 30C, pH 8
0.49
D-glucuronate
P0A8G3
apoenzyme
0.5
D-glucuronate
P0A8G3
reconstituted with Zn2+, 30C, pH 8
0.5
D-glucuronate
C6EHQ2
pH 8.0, 25C, wild-type enzyme
0.55
D-glucuronate
P0A8G3
reconstituted with Cd2+, 30C, pH 8
0.7
D-glucuronate
C6EHQ2
pH 8.0, 25C, mutant H59A; pH 8.0, 25C, mutant H59N
0.82
D-glucuronate
C6EHQ2
pH 8.0, 25C, mutant R414K
0.9
D-glucuronate
-
strain Hfr P4X
1
D-glucuronate
C6EHQ2
pH 8.0, 25C, mutant D412N
1.2
D-glucuronate
-
in presence of 0.1 mM Mn2+
1.3
D-glucuronate
C6EHQ2
pH 8.0, 25C, mutant D238N
1.4
D-glucuronate
C6EHQ2
pH 8.0, 25C, mutant R414M
1.7
D-glucuronate
C6EHQ2
pH 8.0, 25C, mutant W381F
2.5
D-glucuronate
C6EHQ2
pH 8.0, 25C, mutant R302K
2.6
D-glucuronate
C6EHQ2
pH 8.0, 25C, mutant R186K
3.7
D-glucuronate
-
-
8.5
D-glucuronate
P0A8G3
reconstituted with Ni2+, 30C, pH 8
9.4
D-glucuronate
C6EHQ2
pH 8.0, 25C, mutant H35N
10.21
D-glucuronate
C6EHQ2
pH 8.0, 25C, mutant Y60A
21
D-glucuronate
C6EHQ2
pH 8.0, 25C, mutant W381A
38
D-glucuronate
C6EHQ2
pH 8.0, 25C, mutant R186M
39
D-glucuronate
C6EHQ2
pH 8.0, 25C, mutant H35A
56
D-glucuronate
C6EHQ2
pH 8.0, 25C, mutant H297N
200
D-glucuronate
C6EHQ2
pH 8.0, 25C, mutant R302M
220
D-glucuronate
C6EHQ2
pH 8.0, 25C, mutant H297A
0.75
D-Tagaturonate
-
-
additional information
additional information
C6EHQ2
primary isotope effects on the kinetic constants with D-glucuronate and the effects of changes in solvent viscosity are consistent with product release being the rate-limiting step
-
TURNOVER NUMBER [1/s]
SUBSTRATE
ORGANISM
UNIPROT
COMMENTARY
LITERATURE
IMAGE
2.4
D-galacturonate
-
at 30C, pH 8.0
0.6
D-glucuronate
C6EHQ2
pH 8.0, 25C, mutant D412N; pH 8.0, 25C, mutant H33A; pH 8.0, 25C, mutant H59A
0.7
D-glucuronate
C6EHQ2
pH 8.0, 25C, mutant H35A; pH 8.0, 25C, mutant R414M
2.1
D-glucuronate
C6EHQ2
pH 8.0, 25C, mutant H33N
4
D-glucuronate
C6EHQ2
pH 8.0, 25C, mutant H35N
4.7
D-glucuronate
C6EHQ2
pH 8.0, 25C, mutant R186M
5.2
D-glucuronate
-
at 30C, pH 8.0
5.8
D-glucuronate
C6EHQ2
pH 8.0, 25C, mutant R414K
9
D-glucuronate
C6EHQ2
pH 8.0, 25C, mutant D412A
10
D-glucuronate
C6EHQ2
pH 8.0, 25C, mutant H297A
13.9
D-glucuronate
C6EHQ2
pH 8.0, 25C, mutant Y60A
15
D-glucuronate
C6EHQ2
pH 8.0, 25C, mutant H59N
16
D-glucuronate
C6EHQ2
pH 8.0, 25C, mutant W381F
21.7
D-glucuronate
C6EHQ2
pH 8.0, 25C, mutant Y60F
30
D-glucuronate
C6EHQ2
pH 8.0, 25C, mutant H297N
54
D-glucuronate
C6EHQ2
pH 8.0, 25C, mutant R186K
60
D-glucuronate
C6EHQ2
pH 8.0, 25C, mutant D238N
160
D-glucuronate
C6EHQ2
pH 8.0, 25C, mutant R302K
180
D-glucuronate
C6EHQ2
pH 8.0, 25C, mutant R302M
196
D-glucuronate
C6EHQ2
pH 8.0, 25C, wild-type enzyme
250
D-glucuronate
C6EHQ2
pH 8.0, 25C, mutant W381A
kcat/KM VALUE [1/mMs-1]
SUBSTRATE
ORGANISM
UNIPROT
COMMENTARY
LITERATURE
IMAGE
0.018
D-glucuronate
C6EHQ2
pH 8.0, 25C, mutant H35A
339
0.021
D-glucuronate
C6EHQ2
pH 8.0, 25C, mutant D412A
339
0.043
D-glucuronate
C6EHQ2
pH 8.0, 25C, mutant H297A
339
0.054
D-glucuronate
C6EHQ2
pH 8.0, 25C, mutant R414M
339
0.06
D-glucuronate
C6EHQ2
pH 8.0, 25C, mutant D412N
339
0.088
D-glucuronate
C6EHQ2
pH 8.0, 25C, mutant R302M
339
0.13
D-glucuronate
C6EHQ2
pH 8.0, 25C, mutant R186M
339
0.43
D-glucuronate
C6EHQ2
pH 8.0, 25C, mutant H35N
339
0.5
D-glucuronate
C6EHQ2
pH 8.0, 25C, mutant H297N
339
0.83
D-glucuronate
C6EHQ2
pH 8.0, 25C, mutant H59A
339
3
D-glucuronate
C6EHQ2
pH 8.0, 25C, mutant H33A
339
7.1
D-glucuronate
C6EHQ2
pH 8.0, 25C, mutant R414K
339
9.5
D-glucuronate
C6EHQ2
pH 8.0, 25C, mutant W381F
339
12
D-glucuronate
C6EHQ2
pH 8.0, 25C, mutant W381A
339
21
D-glucuronate
C6EHQ2
pH 8.0, 25C, mutant H59N; pH 8.0, 25C, mutant R186K
339
46
D-glucuronate
C6EHQ2
pH 8.0, 25C, mutant D238N
339
47
D-glucuronate
C6EHQ2
pH 8.0, 25C, mutant H33N
339
63
D-glucuronate
C6EHQ2
pH 8.0, 25C, mutant R302K
339
66
D-glucuronate
C6EHQ2
pH 8.0, 25C, mutant Y60A
339
140
D-glucuronate
C6EHQ2
pH 8.0, 25C, mutant Y60F
339
400
D-glucuronate
C6EHQ2
pH 8.0, 25C, wild-type enzyme
339
Ki VALUE [mM]
INHIBITOR
ORGANISM
UNIPROT
COMMENTARY
LITERATURE
IMAGE
0.0021
(2S,3R,4S)-4-(hydroxycarbamoyl)-2,3,4-trihydroxybutanoate
-
at 30C, pH 8.0
0.000013
D-arabinaric acid
P0A8G3
apo and Zn2+ reconstituted enzyme
0.0055
D-arabinaric acid
-
at 30C, pH 8.0
0.00067
D-arabinohydroxamate
P0A8G3
Zn2+ reconstituted enzyme
0.00093
D-arabinohydroxamate
P0A8G3
apo enzyme
0.00043
L-Gulonic acid
P0A8G3
Zn2+ reconstituted enzyme
SPECIFIC ACTIVITY [µmol/min/mg]
ORGANISM
UNIPROT
COMMENTARY
LITERATURE
additional information
-
-
pH OPTIMUM
ORGANISM
UNIPROT
COMMENTARY
LITERATURE
8 - 8.5
-
-
8
C6EHQ2
assay at
additional information
C6EHQ2
the pH-rate profiles for kcat and kcat/Km for URI from Escherichia coli are bellshaped and indicate that one group must be unprotonated and another residue must be protonated for catalytic activity
pH RANGE
ORGANISM
UNIPROT
COMMENTARY
LITERATURE
6 - 8.2
-
pH 6.0: about 50% of maximal activity at pH 6.0 and 8.2
6 - 9
-
pH 6.0: about 30% of maximal activity, pH 9.0: about 40% of maximal activity with D-galacturonate
7.5 - 9
-
pH 7.5: about 55% of maximal activity, pH 9.0: about 75% of maximal activity with glucuronate
TEMPERATURE OPTIMUM
ORGANISM
UNIPROT
COMMENTARY
LITERATURE
25
C6EHQ2
assay at
PDB
SCOP
CATH
ORGANISM
Bacillus halodurans (strain ATCC BAA-125 / DSM 18197 / FERM 7344 / JCM 9153 / C-125)
Bacillus halodurans (strain ATCC BAA-125 / DSM 18197 / FERM 7344 / JCM 9153 / C-125)
Bacillus halodurans (strain ATCC BAA-125 / DSM 18197 / FERM 7344 / JCM 9153 / C-125)
Bacillus halodurans (strain ATCC BAA-125 / DSM 18197 / FERM 7344 / JCM 9153 / C-125)
Bacillus halodurans (strain ATCC BAA-125 / DSM 18197 / FERM 7344 / JCM 9153 / C-125)
Bacillus halodurans (strain ATCC BAA-125 / DSM 18197 / FERM 7344 / JCM 9153 / C-125)
Bacillus halodurans (strain ATCC BAA-125 / DSM 18197 / FERM 7344 / JCM 9153 / C-125)
Bacillus halodurans (strain ATCC BAA-125 / DSM 18197 / FERM 7344 / JCM 9153 / C-125)
Bacillus halodurans (strain ATCC BAA-125 / DSM 18197 / FERM 7344 / JCM 9153 / C-125)
Caulobacter crescentus (strain ATCC 19089 / CB15)
Salmonella typhimurium (strain LT2 / SGSC1412 / ATCC 700720)
Thermotoga maritima (strain ATCC 43589 / MSB8 / DSM 3109 / JCM 10099)
MOLECULAR WEIGHT
ORGANISM
UNIPROT
COMMENTARY
LITERATURE
49000
-
SDS-PAGE
690912
SUBUNITS
ORGANISM
UNIPROT
COMMENTARY
LITERATURE
trimer
-
x-ray crystallography
additional information
-
structure modelling, overview
additional information
C6EHQ2
structure modelling using the crystal structure of URI from Bacillus halodurans, overview
Crystallization/COMMENTARY
ORGANISM
UNIPROT
LITERATURE
complexed with Zn2+, vapour diffusion method, with 45% polypropylene glycol and 0.1 M Bis-Tris, pH 6.5
-
enzyme Bh0493 in complex with substrate D-glucuronate, D-fructuronate, or two inhibitory mimics of the cis-enediol intermediate, hanging drop method at room temperature, B16 mg/ml h0493 in 10 mM HEPES, pH 7.5, 150 mM NaCl, 10 mM methionine, 10% glycerol, 1.0 mM DTT, 0.2 mM ZnCl2, and the corresponding substrate or inhibitor at 40 mM, precipitation solutions are 20% PEG 3350 and 0.2 M sodium citrate, pH 6.0, or 25% PEG 3350, 0.1 M Tris, pH 8.5, and 0.2 M NaCl, X-ray diffraction structure determination and analysis at 1.9-2.2 A resolution
-
STORAGE STABILITY
ORGANISM
UNIPROT
LITERATURE
0-3C, stable for several months without loss of activity
-
-20C, stable for at least 6 months
-
Purification/COMMENTARY
ORGANISM
UNIPROT
LITERATURE
Resource Q column chromatography and Superdex 200 gel filtration
-
of the wild type and recombinant protein, ammonium sulfate fractionation, gel filtration, and ion exchange chromatography
P0A8G3
Cloned/COMMENTARY
ORGANISM
UNIPROT
LITERATURE
expressed in Escherichia coli BL21(DE3) cells
-
overexpression in Escherichia coli
P0A8G3
overexpression in Escherichia coli BL21(DE3)pLysS
-
ENGINEERING
ORGANISM
UNIPROT
COMMENTARY
LITERATURE
D238N
C6EHQ2
site-directed mutagenesis, the mutant shows altered kinetics and zinc content compared to the wild-type enzyme
D412A
C6EHQ2
site-directed mutagenesis, the mutant shows altered kinetics and zinc content compared to the wild-type enzyme
D412N
C6EHQ2
site-directed mutagenesis, the mutant shows altered kinetics and zinc content compared to the wild-type enzyme
H297A
C6EHQ2
site-directed mutagenesis, the mutant shows altered kinetics and zinc content compared to the wild-type enzyme
H297N
C6EHQ2
site-directed mutagenesis, the mutant shows altered kinetics and zinc content compared to the wild-type enzyme
H33A
C6EHQ2
site-directed mutagenesis, the mutant shows altered kinetics and zinc content compared to the wild-type enzyme
H33N
C6EHQ2
site-directed mutagenesis, the mutant shows altered kinetics and zinc content compared to the wild-type enzyme
H35A
C6EHQ2
site-directed mutagenesis, the mutant shows altered kinetics and zinc content compared to the wild-type enzyme
H35N
C6EHQ2
site-directed mutagenesis, the mutant shows altered kinetics and zinc content compared to the wild-type enzyme
H59A
C6EHQ2
site-directed mutagenesis, the mutant shows altered kinetics and zinc content compared to the wild-type enzyme
R186K
C6EHQ2
site-directed mutagenesis, the mutant shows altered kinetics and zinc content compared to the wild-type enzyme
R186M
C6EHQ2
site-directed mutagenesis, the mutant shows altered kinetics and zinc content compared to the wild-type enzyme
R302K
C6EHQ2
site-directed mutagenesis, the mutant shows altered kinetics and zinc content compared to the wild-type enzyme
R302M
C6EHQ2
site-directed mutagenesis, the mutant shows altered kinetics and zinc content compared to the wild-type enzyme
R414K
C6EHQ2
site-directed mutagenesis, the mutant shows altered kinetics and zinc content compared to the wild-type enzyme
R414M
C6EHQ2
site-directed mutagenesis, the mutant shows altered kinetics and zinc content compared to the wild-type enzyme
W381A
C6EHQ2
site-directed mutagenesis, the mutant shows altered kinetics and zinc content compared to the wild-type enzyme
W381F
C6EHQ2
site-directed mutagenesis, the mutant shows altered kinetics and zinc content compared to the wild-type enzyme
Y60A
C6EHQ2
site-directed mutagenesis, the mutant shows altered kinetics and zinc content compared to the wild-type enzyme
Y60F
C6EHQ2
site-directed mutagenesis, the mutant shows altered kinetics and zinc content compared to the wild-type enzyme
H59N
C6EHQ2
site-directed mutagenesis, the mutant shows altered kinetics and zinc content compared to the wild-type enzyme
additional information
C6EHQ2
construction of mutants in association with the active site structure of URI from Bacillus halodurans