This document presents information on the enzymes involved in the metabolic pathway of gluconeogenesis. It discusses 12 key enzymes by name, EC number, classification, source organism, and molecular structure. The enzymes catalyze critical reactions in converting non-carbohydrate precursors into glucose and include ligases, isomerases, transferases, oxidoreductases, and hydrolases. The shapes and structures of the enzymes are tailored to their specific functions in gluconeogenesis.

1. A PRESENTATION ON UNIQUENESS OF ENZYME
INVOLVED IN THE METABOLIC PATHWAY OF -
GLUCONEOGENESIS.
SUBMITTED TO: Dr. TARA KASHAV
SUBMITTED BY:
POOJA KUMARI SHASHI.
M.Sc. LIFE SCIENCE.
BATCH: 2017-2019
ROLL: 10

2. GLUCONEOGENESIS: An intro
 GLUCO: GLUCOSE ; NEO: NEW ; GENESIS: FORMATION.
 Defined as biosynthesis of glucose from non-carbohydrate precursors.
 The major non-carbohydrate precursors are lactate, amino acids ,glycerol and the
carbon skeleton of most amino acids.
 Non –carbohydrate precursors of glucose are first converted into pyruvate or as
oxaloacetate and DHAP.
 A ubiquitous process , present in plants ,animals ,fungi , bacteria and other
microorganisms.
 One of the main mechanism humans and many other animals use to keep blood
glucose level from dropping too low(hypoglycemia).
 Occurs mainy in liver and to some extent in the cortex of kidney.
 This process occurs during periods of fasting,starvation,low carbohydrate diet or
intense exercise and is highly endergonic.

4. REACTION PATHWAY INVOLVED:
(C3H4O3) (C4H4O5) C3H5O6P
.

5. PYRUVATE CARBOXYLASE • E.C. NUMBER : 6.4.1.1
• From Rizobium etli
• Mitochondrial protein.
• Contain Biotin prosthetic
group,covalently linked by
amide bond.
• Composed of 4 identical
subunits,each with catalytic
activity.
• BLUE:biotin carboxylase
domain.
• GREEN:Allosteric linking
domain.
• RED: Biotin binding
domain.
• ORANGE:Carboxyl
transferase domain.
PDB ID: 2QF7

6. PHOSPHOENOLPYRUVATE CARBOXYKINASE (PEPCK)
• E.C. NUMBER: 4.1.1.32
• CLASSIFICATION:LYASE
• ORGANISM: Homo sapiens
• Molecular function:
nucleotide binding,
GTP binding
Metal ion binding etc.
• GTP utilising PEPCK has a
PEP-binding domain and two
kinase motifs to bind GTP and
magnesium.
PDB ID:1KHG

7. C3H5O6P C3H7O7P C3H7O7P C3H8O10P2
.

8. ENOLASE
• EC NUMBER: 4.2.1.11
• Also as: Phosphopyruvate
hydratase.
• Cofactor: mg(2+)
• Metalloenzyme.
• Organism: e.coli
• Dimer of enolase.
• GREEN: N-terminal
domain
• BROWN: Barrel domain
• RED SPHERES: Mg ions

9. PHOSPHOGLYCERATE MUTASE
EC NUMBER : 5.4.2.11
Source organism : E.coli
CLASSIFICATION:ISOMERA
SE.
It do the interconversion of 3-
and2-phosphoglycerate with
2,3-bisphosphoglycerate as the
primer of the reaction.
NOTE:
Bisphosphoglycerate mutase is
sometimes confused with this
,it catalyzes the cenversion of
1,3-bisposphoglycerate to 2,3-
bisphosphoglycerate.
Citrate
molecule(green)
PDB
ID:1E58

10. PHOSPHOGLYCERATE KINASE
• EC NUMBER:2.7.2.3
• CLASSIFICATION;
TRANSFERASE
• Sequences are highly
conserved.
• It has two domain protein
;each domain is composed
of 6 repeats of an alpha or
beta structural motif.
• Ligands: ATP-binding and
nucleotide-binding.
PDB ID: 2X13

12. GLYCERALDEHYDE-3-PHOSPHATE-DEHYDROGENASE
• EC NUMBER: 1.2.1.12
• Classification:
OXIDOREDUCTASE.
• Organism: Homo sapiens
• It contains 4 copies of
Glyceraldehyde-3-phosphate
dehydrogenase.
• 2 non-polymeric entities:
a. 3 copies of
NICOTINAMIDE-
ADENINE-
DINUCLEOTIDE.
b. 3 copies of ZINC ION.
PDB ID:4WNC

13. TRIOSE-PHOSPHATE-ISOMERASE
• EC NUMBER: 5.3.1.1
• Classification : isomerases.
• It contains 2 copies of Triose-
phosphate isomerase.
• 4 non-polymeric entities:
2 copies of POTASSIUM ION.
1 copy of SODIUM ION
1 COPY OF phosphate ion.
1 copy of BROMIDE ION.
POTASSIUM ION
SODIUM ION
PHOSPHATE ION
BROMIDE ION
PDB ID:1NEY

14. FRUCTOSE-1,6-BISPHOSPHATE-ALDOLASE
• EC NUMBER: 4.1.2.13
• Classification:LYASES.
• Source: Homo sapiens.
• It catalyze a reversible
reaction that splits the
aldol,fructose1,6-
bisphosphate into the triose
phosphates
dihydroxyacetone phosphate
(DHAP) and
glyceraldehyde-3-phosphate.
• Cofactor: Zn(2+)
PDB
ID:4ALD

16. FRUCTOSE-1,6-BISPHOSPHATASE
• EC. NUMBER: 3.1.3.11
• Classification:Hydrolase
• It is an enzyme that converts
fructose-1,6-bisphosphate to
fructose-6-phosphate.
• It catalyses the reaction only
in one direction.
• It require metal ions for
catalysis(Mg2+ and Mn2+
being preferred).
PDB ID: 4MJO

17. GLUCOSE-6-PHOSPHATE-ISOMERASE
• EC NUMBER: 5.3.1.9
• Classification: isomerases.
• It catalyzes the reversible isomerization.
• It is a dimer composed of two identical
monomers.
• GPI monomers are made up of two
domains,one made of two separate
segments called the large domains and
the other made of the segment in
between called the small domain.
• The two domains are each alpa beta
alpha sandwiches.
PDB ID :
1JLH

18. GLUCOSE-6-PHOSPHATASE.
• EC NUMBER: 3.1.3.9
• Classification : Hydrolase
• It is an enzyme that hydrolyzes
glucose-6-pospate resulting in the
formation of a phosphate group and
free glucose.
• Consists of 357 amino acids anchored
to the ER by nine transmembrane
helicies.
• Its N-terminal and active sites are
found on the lumen side of the ER and
its C-terminal projects into the
cytoplasm.
• Due to the tight association to the ER
,its exact structure is unknown.
Vanadium containing chloroperoxidase enzyme
with amino acid residues shown in
colour.Vanadium containing chloroperoxidase has
a similar structure and active site as glucose-6-
phosphatase

19. CONCLUSION
ENZYMES CLASSIFICATION
• PYRUVATE CARBOXYLASE LIGASE
• PHOSPHOENOLPYRUVATE
CARBOXYKINASE.
• ENOLASE.
• FRUCTOSE-1,6-BISPHOSPHATE
ALDOLASE.
LYASES
• PHOSPHOGLYCERATE MUTASE
• TRIOSE-PHOSPHATE ISOMERASE.
• GLUCOSE-6-PHOSPHATE
ISOMERASE.
ISOMERASE
• PHOSPHOGLYCERATE KINASE TRANSFERASES
• GLYCERALDEHYDE-3-
PHOSPHATE DEHYDROGENASE.
OXIDOREDUCTA
SE
• FRUCTOSE-1,6-BISPHOSPHATASE
• GLUCOSE-6-PHOSPHATASE.
HYDROLASE
• As one can see
from this table
that the
gluconeogenesis
metabolic
pathway includes
all the 6 classes
of enzymes.

20. • Shape of an enzyme is very important and different type of enzymes have
different shapes and functions because the order and type of amino acids in
their structure is different.
The rate of gluconeogenesis is ultimately controlled by the action of a key
enzyme,fructose-1,6-bisphosphatase