Escherichia coli methionine

Methionine amlnopeptldases Escherichia coli methionine-1 IMAT Col 2.9 Asp ... 

Lowther, W. T., Zhang, Y., Sampson, P. B., et al. (1999) Insights into the mechanism of Escherichia coli methionine aminopeptidase from the structural analysis of reaction products and phosphorus-based transition-state analogues. Biochemistry, 38(45), 14810-14819. 

Oxadiazolyl hydroxamic acids 80 have been evaluated against Escherichia coli methionine aminopeptidase showing potent activity, with IC50 values in the micromolar range and good selectivity toward... 

ACTH, adrenocorticotrophic hormone Met, methionine Met(O), methionine sulfoxide DTT, dithiothreitol L7, L12, Escherichia coli ribosomal proteins Met(0)-L12, L12 containing Met(O) residues a-l-PI, a-1-proteinase inhibitor Met(0)-a-l-PI, a-l-PI... 

Although the pathway has not been established, relatively high yields of trimethyltin from inorganic tin have been observed in yeast concomitant with the degradation of butyltin compounds (Errecalde et al. 1995). Exceptionally, methionine transferase may carry out the methylation of Hg in Neurospora crassa (Landner 1971) and thiopurine methyltransferase the methylation of inorganic Se in Escherichia coli (Ranjard et al. 2003). 

Exceptionally, in Escherichia coli acireductone dioxygenase (enediol dioxygenase) carries out two enzymatic activities that are responsible for the salvage of methionine, but are encoded by the same gene. Whereas one enzyme is dependent on Fe and produces the ketoacid and formate (Figure 3.34a), the other that is nickel-dependent produces the carboxylic acid, formate, and CO (Figure 3.34b) (Dai et al. 1999). 

Isolated polynucleotide clusters from Rhodococcus opacus which encode four polypeptides possessing the activities of a NHase (a and /3 subunits), an auxiliary protein P15K that activates the NHase, and a cobalt transporter protein were expressed in Escherichia coli DSM 14459 cells [34]. Methionine nitrile was added continuously to a suspension of the transformant cells (5.6% w/v of wet cells) in phosphate buffer (50 mM, pH 7.5) at 20 °C, at a rate where the nitrile concentration did not exceed 15 g L 1 while maintaining the pH constant at 7.5. After 320 min, the nitrile was completely converted into amide, corresponding to a final product concentration of 176 gL1.4-Methylthio-a-hydroxybutyramide is readily hydrolyzed with calcium hydroxide, where the calcium salt of 4-methylthio-a-hydroxybutyric acid (MHA) can be directly used as a nutritional supplement in animal feed as an alternative to methionine or MHA. 

To establish whether rifaximin, like the other members of the rifamycin family [36, 58], specifically inhibits bacterial RNA synthesis the effect of this antibiotic as well as that of rifampicin and chloramphenicol on RNA (via 3H-uridine incorporation), DNA (via 3H-thymidine incorporation) and protein (via 35S-methionine incorporation) synthesis was studied in growing cultures of Escherichia coli [59], While chloramphenicol reduced protein synthesis, both rifaximin and rifampicin inhibited RNA synthesis in a concentration-dependent fashion. In contrast, none of them affected 3H-thymidine incorporation into DNA. These data suggest that rifaximin, like rifampicin, inhibits RNA synthesis by binding the (3 subunit of the bacterial DNA-dependent RNA polymerase [60],... 

Pharmacology Anakinra is a recombinant, nonglycosylated form of the human interleukin-1 receptor antagonist (IL-1 Ra). Anakinra differs from native human IL-IRa in that it has a single methionine residue at its amino terminus. It is produced by recombinant DNA technology using an Escherichia coli bacterial expression system. 

M. L. Sinnot and P. J. Smith, Affinity labelling with deaminatively generated carbonium ion. Kinetics and stoicheiometry of die alkylation of methionine-500 of die lacZ p-galactosidase of Escherichia coli by p-D-galactopyranosylmethyl-p-nitrophenyltriazene, Biochem. J., 175 (1978) 525—538. 

Anakinra is a nonglycosylated form of the human IL-1 receptor antagonist (IL-lra). It is produced in a recombinant Escherichia coli expression system and has an additional methionine residue at its amino terminus. In rheumatoid arthritis patients, the amount of naturally occurring IL-lra in the synovial fluid is not sufhcient to counteract the high levels of locally produced IL-1. Anakinra acts as a competitive antagonist of the type 1 IL-1 receptor and decreases the pain and inflammation produced by IL-1. It is administered as a daily subcutaneous injection. 

Isolation of alkaline phosphatase from Escherichia coli in which 85% of the proline residues were replaced by 3,4-dehydro-proline affected the heat lability and ultraviolet spectrum of the protein but the important criteria of catalytic function such as the and were unaltered (12). Massive replacement of methionine by selenomethionine in the 0-galactosidase of E. coli also failed to influence the catalytic activity. Canavanine facilely replaced arginine in the alkaline phosphatase of this bacterium at least 13 and perhaps 20 to 22 arginyl residues were substituted. This replacement by canavanine caused subunit accumulation since the altered subunits did not dimerize to yield the active enzyme (21). Nevertheless, these workers stated "There was also formed, however, a significant amount of enzymatically active protein in which most arginine residues had been replaced by canavanine." An earlier study in which either 7-azatryptophan or tryptazan replaced tryptophan resulted in active protein comparable to the native enzyme (14). 

The cytochrome bS62 from Escherichia coli involves histidine and methionine axial ligands as shown by crystallographic studies.716... 

S. Tokuyama and K. Hatano, Overexpression of the gene for N-acylamino add racemase from Amycolatopsis sp. TS-1-60 in Escherichia coli and continuous production of optically active methionine in a bio-reactor, Appl. Microbiol. Biotechnol. 1996, 44, 774-777. 

Cole, P., and Crothers, D. (1972). Conformational changes of transfer ribonucleic acid. Relaxation kinetics of the early melting transition of methionine transfer ribonucleic acid (Escherichia coli). Biochemistry 11(23), 4368—4374. 

SY Chang, EC McGary, S Chang. Methionine aminopeptidase gene of Escherichia coli is essential for cell growth. J Bacteriol 171 4071-4072, 1989. 

Jarett JT, Drennan CL, Amaratunga M, Scholten JD, Ludwig ML, Matthews RG. A protein radical cage slows photolysis of methylcobalamin in methionine synthase from Escherichia coli. Bioorg Med Chem 1996 4 1237-46. 

Meinnel, T., Y. Mechulam, and S. Blanquet. 1993. Methionine as translation start signal a review of the enzymes of the pathway in Escherichia coli. Biochimie 75,1061-1075. 

Kromer JO, Wittmann C, Schroder H, Heinzle E (2006) Metabolic pathway analysis for rational design of L-methionine production by Escherichia coli and Corynebacterium glutamicum. Metab Eng 8(4) 353-369... 

In elegant work the enantioselectivity of a hydantoinase from Arthrobader species for the production of l-methionine in Escherichia coli has been inverted [87]. The approach is similar to the one used in the evolution of (S)- and ( -selective lipases (see above). All known hydantoinases are selective for D-5-(2-methylthioethyl)hydantoin (d-18) which leads to the accumulation of N-carbamoyl-D-methionine (d-19), conversion being complete if the conditions of dynamic kinetic resolution are upheld [88], in this case by the use of a racemase or pH >8 (Fig. 11.22). 

It has been shown, in several laboratories, that cell-free extracts of Escherichia coli catalyze the formation of [Pg.233]

Hydantoinase-Carbamoylase System for t-Amino Acid Synthesis Despite a number of reports of strains with L-selechve hydantoin-hydrolyzing enzymes [38] the commercial application of the hydantoinase process is stiU restricted to the production of D-amino acids. Processes for the production of L-amino acids are Umited by low space-time yields and high biocatalyst costs. Recently, a new generation of an L-hydantoinase process was developed based on a tailor-made recombinant whole cell biocatalyst. Further reduction of biocatalyst cost by use of recombinant Escherichia coli cells overexpressing hydantoinase, carbamoylase, and hydantoin racemase from Arthrohacter sp. DSM 9771 were achieved. To improve the hydan-toin-converting pathway, the level of expression of the different genes was balanced on the basis of their specific activities. The system has been appUed to the preparation of L-methionine the space-time yield is however still Umited [39]. Improvements in the deracemization process from rac-5-substituted hydantoins to L-amino acids still requires a more selective L-hydantoinase. 

M. S. Kang, D.B. Ha, C.H. Chung, The P-1 Reactive Site Methionine Residue of Ecotin Is Not Cmcial for Its Specificity on Target Proteases - a Potent Inhibitor of Pancreatic Serine Proteases from Escherichia Coli. J. Biol. Chem. 1994,... 

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