Wyniki wyszukiwania

1

Artykuł dostępny w postaci pełnego tekstu - kliknij by otworzyć plik

A new division of bacterial UvrA homologues

100%

Marszalkowska M., Bil M., Kreft L., Olszewski M.

BioTechnologia. Journal of Biotechnology Computational Biology and Bionanotechnology

|

2013

|

tom 94

|

nr 1

2

Cloning and preliminary characterization of a GATC-specific beta2-class DNA:m6A methyltransferase encoded by transposon Tn1549 from Enterococcus spp.

100%

Radlinska M., Piekarowicz A., Galimand M., Bujnicki J. M.

Polish Journal of Microbiology

|

2005

|

tom 54

|

nr 3

A recent study revealed a subfamily of N6-adenine (m⁶A) methyltransferases that comprises a few functionally studied eukaryotic members acting on mRNA and prokaryotic members acting on DNA as well as numerous uncharacterized open reading frames. Here, we report cloning and functional characterization of a prokaryotic member of this family encoded by transposon Tn1549 from Enterococcus spp.

3

Purification and characterization of GlcNAc-6-P 2-epimerase from Escherichia coli K92

100%

Ferrero M. A., Martinez-Blanco H., Lopez-Velasco F. F., Ezquerro-Saenz C., Navasa N., Rodriguez-Aparicio L. B.

Acta Biochimica Polonica

|

2007

|

tom 54

|

nr 2

N-Acetylmannosamine (ManNAc) is the first committed intermediate in sialic acid metabolism. Thus, the mechanisms that control intracellular ManNAc levels are important regulators of sialic acid production. In prokaryotic organisms, UDP-N-acetylglucosamine (GlcNAc) 2-epimerase and GlcNAc-6-P 2-epimerase are two enzymes capable of generating ManNAc from UDP-GlcNAc and GlcNAc-6-P, respectively. We have purified for the first time native GlcNAc-6-P 2-epimerase from bacterial source to apparent homogeneity (1 200 fold) using Butyl-agarose, DEAE-FPLC and Mannose-6-P-agarose chromatography. By SDS/PAGE the pure enzyme showed a molecular mass of 38.4 ± 0.2 kDa. The maximum activity was achieved at pH 7.8 and 37oC. Under these conditions, the Km calculated for GlcNAc-6-P was 1.5 mM. The 2-epimerase activity was activated by Na++ and inhibited by mannose-6-P but not mannose-1-P. Genetic analysis revealed high homology with bacterial isomerases. GlcNAc-6-P 2-epimerase from E. coli K92 is a ManNAc-inducible protein and is detected from the early logarithmic phase of growth. Our results indicate that, unlike UDP-GlcNAc 2-epimerase, which promotes the biosynthesis of sialic acid, GlcNAc-6-P 2-epimerase plays a catabolic role. When E. coli grows using ManNAc as a carbon source, this enzyme converts the intracellular ManNAc-6-P generated into GlcNAc-6-P, diverting the metabolic flux of ManNAc to GlcNAc.

4

Morphological and physiological characterization of the delta-psaL mutant of cyanobacterium Synechocystis PCC6803

80%

Klodawska K., Kis M., Malec P., Kovacs L., Gombos Z., Strzalka K.

BioTechnologia. Journal of Biotechnology Computational Biology and Bionanotechnology

|

2013

|

tom 94

|

nr 3

5

DNA methyltransferases of Neisseria gonorrhoeae

80%

Piekarowicz A., Radlinska M., Wiernicka-Gnas M.

Bulletin of the Polish Academy of Sciences. Biological Sciences

|

1996

|

tom 44

|

nr 3-4

6

Reduction of bacterial genome size and expansion resulting from obligate intracellular life style and adaptation to soil habitat

80%

Stepkowski T., Legocki A. B.

Acta Biochimica Polonica

|

2001

|

tom 48

|

nr 2

Prokaryotic or gan isms are ex posed in the course of evo lu tion to var i ous im pacts, result ing of ten in dras tic changes of their ge nome size. De pending on cir cum stances, the same lin eage may di verge into spe cies hav ing sub stan tially re duced genomes, or such whose genomes have un der gone con sid er able en large ment. Ge nome re duc tion is a con se quence of ob li gate intracellular life style ren der ing nu mer ous genes ex pend able. An other con se quence of intracellular life style is re duc tion of ef fec tive pop u la- tion size and lim ited pos si bil ity of gene ac quire mentvia lat eral trans fer. This causes a state of re laxed se lec tion re sult ing in ac cu mu la tion of mildly del e te ri ous mu ta tions that can not be cor rected by re com bi na tion with the wild type copy. Thus, gene loss is usually irreversible. Additionally, constant environment of the eukaryotic cell renders that some bac te rial genes in volved in DNA re pair are ex pand able. The loss of these genes is a prob a ble cause of mutational bias re sult ing in a high A+T con tent. While causes of genome reduction are rather indisputable, those resulting in genome ex pan sion seem to be less ob vi ous. Pre sum ably, the ge nome en large ment is an indirect consequence of adaptation to changing environmental conditions and requires the ac qui si tion and in te gra tion of nu mer ous genes. It seems that the need for a great number of capabilities is common among soil bacteria irrespective of their phylo gen etic re la tion ship. How ever, this would not be pos si ble if soil bac te ria lacked in dig e nous abil i ties to ex change and ac cu mu late ge netic in for ma tion. The lat ter are con sid er ably fa cil i tated when house keep ing genes are phys i cally sep a rated from adaptive loci which are useful only in certain circum stances.

7

Qualitative analysis of stress proteins induced by cadmium in the blue mussel Mytilus trossulus

80%

Radlowska M., Pempkowiak J.

Oceanological Studies

|

1996

|

tom 25

|

nr 3

8

DNA methyltransferases of Neisseria gonorrhoeae

80%

Piekarowicz A.

Acta Microbiologica Polonica

|

1994

|

tom 43

|

nr 3-4

Ograniczanie wyników

A new division of bacterial UvrA homologues

Cloning and preliminary characterization of a GATC-specific beta2-class DNA:m6A methyltransferase encoded by transposon Tn1549 from Enterococcus spp.

Purification and characterization of GlcNAc-6-P 2-epimerase from Escherichia coli K92

Morphological and physiological characterization of the delta-psaL mutant of cyanobacterium Synechocystis PCC6803

DNA methyltransferases of Neisseria gonorrhoeae

Reduction of bacterial genome size and expansion resulting from obligate intracellular life style and adaptation to soil habitat

Qualitative analysis of stress proteins induced by cadmium in the blue mussel Mytilus trossulus

DNA methyltransferases of Neisseria gonorrhoeae