Browsing Pathways

Phospholipids are membrane components in E. coli. The major phospholipids of E. coli are phosphatidylethanolamine, phosphatidylglycerol, and cardiolipin. All phospholipids contain sn-glycerol-3-phosphate esterified with fatty acids at the sn-1 and sn-2 positions. The reaction starts from a glycerone phosphate (dihydroxyacetone phosphate) produced in glycolysis. The glycerone phosphate is transformed into an sn-glycerol 3-phosphate (glycerol 3 phosphate) by NADPH-driven glycerol-3-phosphate dehydrogenase. sn-Glycerol 3-phosphate is transformed to a 1-acyl-sn-glycerol 3-phosphate (lysophosphatidic acid). This can be achieved by an sn-glycerol-3-phosphate acyltransferase that interacts either with a long-chain acyl-CoA or with an acyl-[acp]. The 1-acyl-sn-glycerol 3-phosphate is transformed into a 1,2-diacyl-sn-glycerol 3-phosphate (phosphatidic acid) through a 1-acylglycerol-3-phosphate O-acyltransferase. This compound is then converted into a CPD-diacylglycerol through a CTP phosphatidate cytididyltransferase. CPD-diacylglycerol can be transformed either into an L-1-phosphatidylserine or an L-1-phosphatidylglycerol-phosphate through a phosphatidylserine synthase or a phosphatidylglycerophosphate synthase, respectively. The L-1-phosphatidylserine transforms into L-1-phosphatidylethanolamine through a phosphatidylserine decarboxylase. On the other hand, L-1-phosphatidylglycerol-phosphate gets transformed into an L-1-phosphatidyl-glycerol through a phosphatidylglycerophosphatase. These 2 products combine to produce a cardiolipin and an ethanolamine. The L-1 phosphatidyl-glycerol can also interact with cardiolipin synthase resulting in a glycerol and a cardiolipin.

Phospholipids are membrane components in E. coli. The major phospholipids of E. coli are phosphatidylethanolamine, phosphatidylglycerol, and cardiolipin. All phospholipids contain sn-glycerol-3-phosphate esterified with fatty acids at the sn-1 and sn-2 positions. The reaction starts from a glycerone phosphate (dihydroxyacetone phosphate) produced in glycolysis. The glycerone phosphate is transformed into an sn-glycerol 3-phosphate (glycerol 3 phosphate) by NADPH-driven glycerol-3-phosphate dehydrogenase. sn-Glycerol 3-phosphate is transformed to a 1-acyl-sn-glycerol 3-phosphate (lysophosphatidic acid). This can be achieved by an sn-glycerol-3-phosphate acyltransferase that interacts either with a long-chain acyl-CoA or with an acyl-[acp]. The 1-acyl-sn-glycerol 3-phosphate is transformed into a 1,2-diacyl-sn-glycerol 3-phosphate (phosphatidic acid) through a 1-acylglycerol-3-phosphate O-acyltransferase. This compound is then converted into a CPD-diacylglycerol through a CTP phosphatidate cytididyltransferase. CPD-diacylglycerol can be transformed either into an L-1-phosphatidylserine or an L-1-phosphatidylglycerol-phosphate through a phosphatidylserine synthase or a phosphatidylglycerophosphate synthase, respectively. The L-1-phosphatidylserine transforms into L-1-phosphatidylethanolamine through a phosphatidylserine decarboxylase. On the other hand, L-1-phosphatidylglycerol-phosphate gets transformed into an L-1-phosphatidyl-glycerol through a phosphatidylglycerophosphatase. These 2 products combine to produce a cardiolipin and an ethanolamine. The L-1 phosphatidyl-glycerol can also interact with cardiolipin synthase resulting in a glycerol and a cardiolipin.

Phospholipids are membrane components in E. coli. The major phospholipids of E. coli are phosphatidylethanolamine, phosphatidylglycerol, and cardiolipin. All phospholipids contain sn-glycerol-3-phosphate esterified with fatty acids at the sn-1 and sn-2 positions. The reaction starts from a glycerone phosphate (dihydroxyacetone phosphate) produced in glycolysis. The glycerone phosphate is transformed into an sn-glycerol 3-phosphate (glycerol 3 phosphate) by NADPH-driven glycerol-3-phosphate dehydrogenase. sn-Glycerol 3-phosphate is transformed to a 1-acyl-sn-glycerol 3-phosphate (lysophosphatidic acid). This can be achieved by an sn-glycerol-3-phosphate acyltransferase that interacts either with a long-chain acyl-CoA or with an acyl-[acp]. The 1-acyl-sn-glycerol 3-phosphate is transformed into a 1,2-diacyl-sn-glycerol 3-phosphate (phosphatidic acid) through a 1-acylglycerol-3-phosphate O-acyltransferase. This compound is then converted into a CPD-diacylglycerol through a CTP phosphatidate cytididyltransferase. CPD-diacylglycerol can be transformed either into an L-1-phosphatidylserine or an L-1-phosphatidylglycerol-phosphate through a phosphatidylserine synthase or a phosphatidylglycerophosphate synthase, respectively. The L-1-phosphatidylserine transforms into L-1-phosphatidylethanolamine through a phosphatidylserine decarboxylase. On the other hand, L-1-phosphatidylglycerol-phosphate gets transformed into an L-1-phosphatidyl-glycerol through a phosphatidylglycerophosphatase. These 2 products combine to produce a cardiolipin and an ethanolamine. The L-1 phosphatidyl-glycerol can also interact with cardiolipin synthase resulting in a glycerol and a cardiolipin.

Phospholipids are membrane components in E. coli. The major phospholipids of E. coli are phosphatidylethanolamine, phosphatidylglycerol, and cardiolipin. All phospholipids contain sn-glycerol-3-phosphate esterified with fatty acids at the sn-1 and sn-2 positions. The reaction starts from a glycerone phosphate (dihydroxyacetone phosphate) produced in glycolysis. The glycerone phosphate is transformed into an sn-glycerol 3-phosphate (glycerol 3 phosphate) by NADPH-driven glycerol-3-phosphate dehydrogenase. sn-Glycerol 3-phosphate is transformed to a 1-acyl-sn-glycerol 3-phosphate (lysophosphatidic acid). This can be achieved by an sn-glycerol-3-phosphate acyltransferase that interacts either with a long-chain acyl-CoA or with an acyl-[acp]. The 1-acyl-sn-glycerol 3-phosphate is transformed into a 1,2-diacyl-sn-glycerol 3-phosphate (phosphatidic acid) through a 1-acylglycerol-3-phosphate O-acyltransferase. This compound is then converted into a CPD-diacylglycerol through a CTP phosphatidate cytididyltransferase. CPD-diacylglycerol can be transformed either into an L-1-phosphatidylserine or an L-1-phosphatidylglycerol-phosphate through a phosphatidylserine synthase or a phosphatidylglycerophosphate synthase, respectively. The L-1-phosphatidylserine transforms into L-1-phosphatidylethanolamine through a phosphatidylserine decarboxylase. On the other hand, L-1-phosphatidylglycerol-phosphate gets transformed into an L-1-phosphatidyl-glycerol through a phosphatidylglycerophosphatase. These 2 products combine to produce a cardiolipin and an ethanolamine. The L-1 phosphatidyl-glycerol can also interact with cardiolipin synthase resulting in a glycerol and a cardiolipin.

Phospholipids are membrane components in E. coli. The major phospholipids of E. coli are phosphatidylethanolamine, phosphatidylglycerol, and cardiolipin. All phospholipids contain sn-glycerol-3-phosphate esterified with fatty acids at the sn-1 and sn-2 positions. The reaction starts from a glycerone phosphate (dihydroxyacetone phosphate) produced in glycolysis. The glycerone phosphate is transformed into an sn-glycerol 3-phosphate (glycerol 3 phosphate) by NADPH-driven glycerol-3-phosphate dehydrogenase. sn-Glycerol 3-phosphate is transformed to a 1-acyl-sn-glycerol 3-phosphate (lysophosphatidic acid). This can be achieved by an sn-glycerol-3-phosphate acyltransferase that interacts either with a long-chain acyl-CoA or with an acyl-[acp]. The 1-acyl-sn-glycerol 3-phosphate is transformed into a 1,2-diacyl-sn-glycerol 3-phosphate (phosphatidic acid) through a 1-acylglycerol-3-phosphate O-acyltransferase. This compound is then converted into a CPD-diacylglycerol through a CTP phosphatidate cytididyltransferase. CPD-diacylglycerol can be transformed either into an L-1-phosphatidylserine or an L-1-phosphatidylglycerol-phosphate through a phosphatidylserine synthase or a phosphatidylglycerophosphate synthase, respectively. The L-1-phosphatidylserine transforms into L-1-phosphatidylethanolamine through a phosphatidylserine decarboxylase. On the other hand, L-1-phosphatidylglycerol-phosphate gets transformed into an L-1-phosphatidyl-glycerol through a phosphatidylglycerophosphatase. These 2 products combine to produce a cardiolipin and an ethanolamine. The L-1 phosphatidyl-glycerol can also interact with cardiolipin synthase resulting in a glycerol and a cardiolipin.

Benzoate, an environmental pollutant, is utilized by bacteria such as Aromatoleum aromaticum to yield energy and carbon. While the precise transport mechanisms remain under research, it is proposed that benzoate is transported across the cell membrane passively or actively via transport proteins such as permeases and porins. Benzoate is then converted to benzoyl-CoA by benzoate-CoA ligase. Benzoyl-CoA is then used for phenylalanine metabolism and processes e.g., biosynthesis of alkaloids

Phospholipids are membrane components in E. coli. The major phospholipids of E. coli are phosphatidylethanolamine, phosphatidylglycerol, and cardiolipin. All phospholipids contain sn-glycerol-3-phosphate esterified with fatty acids at the sn-1 and sn-2 positions. The reaction starts from a glycerone phosphate (dihydroxyacetone phosphate) produced in glycolysis. The glycerone phosphate is transformed into an sn-glycerol 3-phosphate (glycerol 3 phosphate) by NADPH-driven glycerol-3-phosphate dehydrogenase. sn-Glycerol 3-phosphate is transformed to a 1-acyl-sn-glycerol 3-phosphate (lysophosphatidic acid). This can be achieved by an sn-glycerol-3-phosphate acyltransferase that interacts either with a long-chain acyl-CoA or with an acyl-[acp]. The 1-acyl-sn-glycerol 3-phosphate is transformed into a 1,2-diacyl-sn-glycerol 3-phosphate (phosphatidic acid) through a 1-acylglycerol-3-phosphate O-acyltransferase. This compound is then converted into a CPD-diacylglycerol through a CTP phosphatidate cytididyltransferase. CPD-diacylglycerol can be transformed either into an L-1-phosphatidylserine or an L-1-phosphatidylglycerol-phosphate through a phosphatidylserine synthase or a phosphatidylglycerophosphate synthase, respectively. The L-1-phosphatidylserine transforms into L-1-phosphatidylethanolamine through a phosphatidylserine decarboxylase. On the other hand, L-1-phosphatidylglycerol-phosphate gets transformed into an L-1-phosphatidyl-glycerol through a phosphatidylglycerophosphatase. These 2 products combine to produce a cardiolipin and an ethanolamine. The L-1 phosphatidyl-glycerol can also interact with cardiolipin synthase resulting in a glycerol and a cardiolipin.

Fructose metabolism begins with the transport of beta-D-glucose 6-phosphate through a glucose PTS permease. This compound is isomerized by a glucose-6-phosphate isomerase resulting in fructose 6-phosphate. This compound can be phosphorylated by two different enzymes: a pyridoxal phosphatase/fructose 1,6-bisphosphatase or an ATP-driven 6-phosphofructokinase-1, resulting in fructose 1,6-biphosphate. This compound can either react with a fructose bisphosphate aldolase class 1 resulting in D-glyceraldehyde 3-phosphate and dihydroxyacetone phosphate or through a fructose biphosphate aldolase class 2 resulting in D-glyceraldehyde 3-phosphate. This compound can then either react in a reversible triosephosphate isomerase resulting in dihydroxyacetone phosphate or react with a phosphate through an NAD-dependent glyceraldehyde 3-phosphate dehydrogenase resulting in glyceric acid 1,3-biphosphate. This compound is dephosphorylated by a phosphoglycerate kinase resulting in 3-phosphoglyceric acid. This compound, in turn, can either react with a 2,3-bisphosphoglycerate-independent phosphoglycerate mutase or a 2,3-bisphosphoglycerate-independent phosphoglycerate mutase resulting in 2-phospho-D-glyceric acid. This compound interacts with an enolase resulting in a phosphoenolpyruvic acid and water. Phosphoenolpyruvic acid can react either through an AMP-driven phosphoenoylpyruvate synthase or an ADP-driven pyruvate kinase protein complex resulting in pyruvic acid. The pyruvic acid reacts with CoA through an NAD-driven pyruvate dehydrogenase complex resulting in carbon dioxide and an acetyl-CoA which gets incorporated into the TCA cycle pathway.

The S-adenosyl-L-methionine cycle starts with S-adenosyl-L-methionine reacting with (a demethylated methyl donor ) dimethylglycine resulting in the release of a hydrogen ion, a betain (a methylated methyl donor) and a S-adenosyl-L-homocysteine. The s-adenosyl-L-homocysteine reacts with a water molecule through a S-adenosylhomocysteine nucleosidase resulting in the release of a adenine and a ribosyl-L-homocysteine. This compound in turn reacts with a s-ribosylhomocysteine lyase resulting in the release of a l-homocysteine and a autoinducer 2. The L-homocysteine reacts with a N5-methyl-tetrahydropteroyl tri-L-glutamate through a methionine synthase resulting in the release of a tetrahydropteroyl tri-L-glutamate and a methione. The methionine in turn reacts with a water molecule and ATP molecule through a methionine adenosyltransferase resulting in the release of a diphosphate, a phosphate and a s-adenosyl-L-methionine.

Cardiolipin (CL) is an important component of the inner mitochondrial membrane where it constitutes about 20% of the total lipid composition. It is essential for the optimal function of numerous enzymes that are involved in mitochondrial energy metabolism (Wikipedia). Cardiolipin biosynthesis occurs mainly in the mitochondria, but there also exists an alternative synthesis route for CDP-diacylglycerol that takes place in the endoplasmic reticulum. This second route may supplement this pathway. All membrane-localized enzymes are coloured dark green in the image. First, dihydroxyacetone phosphate (or glycerone phosphate) from glycolysis is used by the cytosolic enzyme glycerol-3-phosphate dehydrogenase [NAD(+)] to synthesize sn-glycerol 3-phosphate. Second, the mitochondrial outer membrane enzyme glycerol-3-phosphate acyltransferase esterifies an acyl-group to the sn-1 position of sn-glycerol 3-phosphate to form 1-acyl-sn-glycerol 3-phosphate (lysophosphatidic acid or LPA). Third, the enzyme 1-acyl-sn-glycerol-3-phosphate acyltransferase converts LPA into phosphatidic acid (PA or 1,2-diacyl-sn-glycerol 3-phosphate) by esterifying an acyl-group to the sn-2 position of the glycerol backbone. PA is then transferred to the inner mitochondrial membrane to continue cardiolipin synthesis. Fourth, magnesium-dependent phosphatidate cytidylyltransferase catalyzes the conversion of PA into CDP-diacylglycerol. Fifth, CDP-diacylglycerol--glycerol-3-phosphate 3-phosphatidyltransferase synthesizes phosphatidylglycerophosphate (PGP). Sixth, phosphatidylglycerophosphatase and protein-tyrosine phosphatase dephosphorylates PGP to form phosphatidylglycerol (PG). Last, cardiolipin synthase catalyzes the synthesis of cardiolipin by transferring a phosphatidyl group from a second CDP-diacylglycerol to PG. It requires a divalent metal cation cofactor.