Glutamic acid biosynthesis

Q. Wu, H. Xu, N. Shi, J. Yao, S. Li, P. Ouyang, Improvement of poly (gamma-glutamic acid) biosynthesis and redistribution of metabolic flux with the presence of different additives in Bacillus subtilis CGMCC 0833, Appl. Microbiol. Biotechnol. 79 (2008) 527-535. 

Zhang D, Xu Z, Xu H, Feng X, Li S, Cai H, Wei Y, Ouyang P. (2011). Improvement of poly(y-glutamic acid) biosynthesis and quantitative metabolic flux analysis of a two-stage strategy for agitation speed control in the culture of Bacillus subtilis NX-2. Biotechnol Bioproc Eng, 16, 1144-1151. 

Fig. 2. L-Glutamic acid. Biosynthesis of L-ornithine and L-proline from L-glutamic acid.

Figure 11.4 Metabolic reactions related to glutamic acid biosynthesis in C. glutamicum. GS, glutamine synthetase GOGAT, glutamate synthase (glutamate-oxoglutarate aminotransferase) and GDH, glutamate dehydrogenase.

The 20 ammo acids listed m Table 27 1 are biosynthesized by a number of different path ways and we will touch on only a few of them m an introductory way We will exam me the biosynthesis of glutamic acid first because it illustrates a biochemical process analogous to a reaction we discussed earlier m the context of amine synthesis reductive ammatwn (Section 22 10)... 

L Glutamic acid is not an essential ammo acid It need not be present m the diet because animals can biosynthesize it from sources of a ketoglutaric acid It is however a key intermediate m the biosynthesis of other ammo acids by a process known as transamination L Alanine for example is formed from pyruvic acid by transamination from L glutamic acid... 

Nevertheless the biosynthesis of glutamine proceeds from glutamic acid The dif ference is that the endergonic process m Equation 1 is coupled with the strongly exer gome hydrolysis of ATP... 

Microorganisms requite several minerals such as ferrous and potassium ions which play important roles in glutamic acid fermentation. Other important culture conditions include regulating aeration stirring. The biosynthesis of L-glutamic acid is performed under regulated aerobic conditions. 

The enzymes glutamate dehydrogenase, glutamine synthetase, and aminotransferases occupy central positions in amino acid biosynthesis. The combined effect of... 

Fig. 8.1 Biosynthesis of peptidoglycan. The large circles represent A -acetylglucosamine orN-acetylmuramic acid to the latter is linked initially a pentapeptide chain comprising L-alanine, D-glutamic acid and meso-diaminopiraelic acid (small circles) terminating in two D-alanine residues (small, darker circles). The lipid molecule is undecaprenyl phosphate. In the initial (cytoplasm) stage where inhibition by the antibiotic D-cycloserine is shown, two molecules of Dalanine (small circles) are converted by an isomerase to the D-forms (small, darker circles), alter which a ligase joins the two D-alanines together to produce a D-alanyl-D-alanine dipeptide.

Nguyen, K.T., Kau, D., Gu, J.Q. et al. (2006) A glutamic acid 3-methyltransferase encoded by an accessory gene locus important for daptomycin biosynthesis in Streptomyces roseosporus. Molecular Microbiology, 61 (5), 1294-1307. 

Amino Acid Biosynthesis Aromatic amino acid family Aspartate family Glutamate family Pyruvate family Serine family Histidine family Other... 

Sterol biosynthesis Bile acid biosynthesis C2rSteroid hormone metabolism Androgen and estrogen metabolism Nucleotide Metabolism Purine metabolism Pyrimidine metabolism Nucleotide sugar metabolism Amino sugar metabolism Amino Acid Metabolism Glutamate metabolism Alanine and aspartate metabolism Glycine, serine, and threonine metabolism... 

There is only a small selection of nonprotein amino acids that contain carbonyl groups in the form of ketone, aldehyde, and carboxylic acid moieties, as part of the side chain. The examples given in Table 6 are components of nonribosomal peptides isolated from bacteria or fungi and siderophores from bacteria. The biosynthesis of these amino acids is not clear however, some of the amino acids with carboxylic acid side chains may be traced back to the L-a-amino acids aspartic acid and glutamic acid. 

GABA synthesis inhibitors act on the enzymes involved in the decarboxylation and transamination of GABA. Glutamic acid decarboxylase (GAD), the first enzyme in GABA biosynthesis, is inhibited easily by carbonyl reagents such as hydrazines [e.g., hydrazinopropionic acid (4.164) or isonicotinic acid hydrazide (4.165)], which trap pyridoxal, the essential cofactor of the enzyme. A more specific inhibitor is allylglycine (4.166). All of these compounds cause seizures and convulsions because they decrease the concentration of GABA. 

One substance that has been found to be an essential requirement for the biosynthesis of DNA is the cobalt-containing vitamin B12 (42). Ever since this substance was first isolated and its structure determined, there has been a widespread search for the specific reactions that it mediates. The first such reaction was discovered by Barker, Weissbach, and Smyth (5), when they examined the enzymatic isomerization of glutamic acid to /3-methylaspartic acid. They were... 

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