Overproduction of mycobacterial ribosomal protein S13 induces catalase/peroxidase activity and hypersensitivity to isoniazid in Mycobacterium smegmatis

Synechococcus PCC 7942, a cyanobacterium, possesses catalase–peroxidase as the sole hydrogen peroxide-scavenging system. The enzyme has been purified to electrophoretic homogenenity from the cells. The native enzyme had a molecular mass of 150 kDa and was composed of two identical subunits of molecular mass 79 kDa. The apparent Km value of the catalase activity for H2O2 was 4.2±0.27 mM and the kcat value was 2.6×104 s-1. The enzyme contained high catalase activity and an appreciable peroxidase activity with o-dianisidine and pyrogallol. The catalase activity was not inhibited by 3-amino-1,2,4-triazole but by KCN and NaN3 (apparent Ki values 19.3±0.84 and 20.2±0.95 μM respectively). The enzyme showed an absorption spectrum of typical protohaem and contained one protohaem molecule per dimer. The gene encoding catalase–peroxidase was cloned from the chromosomal DNA of Synechococcus PCC 7942. A 2160 bp open reading frame (ORF), coding a catalase–peroxidase of 720 amino acid residues (approx. 79.9 kDa), was observed. The deduced amino acid sequence coincided with that of the N-terminus of the purified enzyme and showed a remarkable similarity to those of a family of catalase–peroxidases of prokaryotic cells. Escherichia coli BL21(DE3)plysS, harbouring a recombinant plasmid containing the catalase–peroxidase gene, produced a large amount of proteins that co-migrated on SDS/PAGE with the native enzyme. The recombinant enzyme showed the same ratio of catalase activity to peroxidase activity with o-dianisidine and the same Km for H2O2 as the native enzyme.

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Human ribosomal protein S13 inhibits splicing of its own pre-mRNA

Molecular Biology ◽

10.1134/s0026893307010074 ◽

2007 ◽

Vol 41 (1) ◽

pp. 44-51 ◽

Cited By ~ 5

Author(s):

N. M. Parakhnevitch ◽

A. V. Ivanov ◽

A. A. Malygin ◽

G. G. Karpova

Keyword(s):

Ribosomal Protein ◽

Human Ribosomal Protein ◽

Ribosomal Protein S13 ◽

Human Ribosomal Protein S13

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Effect of fungicides on the enzymatic activity of the antioxidant system and the chlorophyll content in lupine plants during seed dressing

Karantin i zahist roslin ◽

10.36495/2312-0614.2020.7-9.3-6 ◽

2020 ◽

pp. 3-6

Author(s):

O. Borzykh ◽

O. Tsurkan ◽

L. Chervyakova ◽

T. Panchenko

Keyword(s):

Analytical Chemistry ◽

Chlorophyll Content ◽

Peroxidase Activity ◽

Catalase Activity ◽

Control Level ◽

Growth Stages ◽

Enzymatic System ◽

Initial Growth ◽

Seed Dressing ◽

Catalase Peroxidase

Goal. The effect of fungicides on the dynamics of the activity of peroxidase, catalase (CAT) and chlorophyll content in lupine plants during seed dressing has been established. Methods. Laboratory and vegetation researches were conducted in the laboratory of analytical chemistry of pesticides of the Institute of Plant Protection. Yellow lupine (Lupinus luteus L.), variety Obriy has been grown. The objects of research were fungicides triticonazol (40 g/t) and its combination with prochloraz (120 g/t). Determination of the content of fungicides in plants was carried out using chromatographic methods according to officially approved methods and methods developed in the laboratory of analytical chemistry of pesticides. Chlorophyll content and peroxidase activity were measured by colorimetric method, catalase activity — by titrimetric method. Results. According to the research results, the varying sensitivity of the enzymatic system of antioxidant defense (catalase, peroxidase) in response to seed dressing by fungicides was recorded. It showed that on the 10th day after sowing, content of triticonazol in plants was 0.8 mg/kg, and the peroxidase activity was similar to that in untreated plants. Subsequently, against the background of a decrease in the content of the active substance, a gradual activation of the enzyme was observed. Catalase activity also gradually increased beginning from the 14th day, and on the 30th day it exceeded the corresponding control indicator by 40%. When using a combination of triticonazol with prochloraz, the disturbance in the balance of peroxidase catalase was more significant. However, by the phase of 7—8 leaves, with a minimal total content of fungicides (0.38 mg/kg), the enzyme activity approached the control level, which is associated with the restoration of plant homeostasis and the formation of its adaptive potential under stress conditions. The stimulating effect of these fungicides on chlorophyll content at the initial growth stages of lupine was established. The chlorophyll concentration in fungicides-treated plants exceeded the control indicator by 11—29%. Conclusions. The use of systemic triazole fungicides to protect seedlings, improves the photosynthetic activity of plants and at the same time acts as a stress factor that activates protecting enzymes (catalase, peroxidase), which trigger the development of protective adaptive reactions of plants.

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The yeast omnipotent suppressor SUP46 encodes a ribosomal protein which is a functional and structural homolog of the Escherichia coli S4 ram protein.

Genetics ◽

10.1093/genetics/132.2.375 ◽

1992 ◽

Vol 132 (2) ◽

pp. 375-386 ◽

Cited By ~ 1

Author(s):

A Vincent ◽

S W Liebman

Keyword(s):

Escherichia Coli ◽

Ribosomal Protein ◽

Dna Sequences ◽

Ribosomal Proteins ◽

Amino Acid Sequences ◽

Ribosomal Protein Genes ◽

Significant Homology ◽

A Cell ◽

Functional Equivalent ◽

Ribosomal Protein S13

Abstract The accurate synthesis of proteins is crucial to the existence of a cell. In yeast, several genes that affect the fidelity of translation have been identified (e.g., omnipotent suppressors, antisuppressors and allosuppressors). We have found that the dominant omnipotent suppressor SUP46 encodes the yeast ribosomal protein S13. S13 is encoded by two similar genes, but only the sup46 copy of the gene is able to fully complement the recessive phenotypes of SUP46 mutations. Both copies of the S13 genes contain introns. Unlike the introns of other duplicated ribosomal protein genes which are highly diverged, the duplicated S13 genes have two nearly identical DNA sequences of 25 and 31 bp in length within their introns. The SUP46 protein has significant homology to the S4 ribosomal protein in prokaryotic-type ribosomes. S4 is encoded by one of the ram (ribosomal ambiguity) genes in Escherichia coli which are the functional equivalent of omnipotent suppressors in yeast. Thus, SUP46 and S4 demonstrate functional as well as sequence conservation between prokaryotic and eukaryotic ribosomal proteins. SUP46 and S4 are most similar in their central amino acid sequences. Interestingly, the alterations resulting from the SUP46 mutations and the segment of the S4 protein involved in binding to the 16S rRNA are within this most conserved region.

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