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Analysis of essentiality of glmM gene coding for phosphoglucosamine mutase of Streptococcus pneumoniae.
Krupička, Jiří ; Branny, Pavel (advisor) ; Čáp, Michal (referee)
Phosphoglucosamine mutase (GlmM) is an enzyme of bacterial cell wall biosynthesis. The main aim of this thesis was to find out, whether gene glmM is essential for viability of Streptococcus pneumoniae. Therefore, we prepared merodiploid strain containing two copies of glmM; the genomic gene and ectopic copy under control of zinc inducible promoter. Subsequently, depletion strain was prepared by deletion of genomic copy of glmM. This strain was further used for analysis of viability and phenotype features in the medium containing various concentrations of zinc ions, an inducer of ectopic glmM expression. We found out, that the viability of this strain was strictly dependent on the concentration of inducer and further, that depletion of GlmM resulted in remarkable morphological defects. The rescue of mutant strain was observed after addition of inducer up to the level of the control sample. These results have provided the evidence of glmM essentiality for S. pneumoniae viability. Furthermore, we analyzed, whether phosphorylation of key amino acid residues, S99 and S101, is essential for GlmM functionality. Four different strains were prepared by means of site-directed mutagenesis expressing glmM with substitutions of key serine residues for alanine or glutamic acid. Since deletion of chromosomal locus in...
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Non-conventional bacterial signaling pathways
Krupička, Jiří ; Branny, Pavel (advisor) ; Beranová, Jana (referee)
Two component systems were traditionally considered as main phosphorylation systems of bacteria involved in cell signalling. Recently, attention focuses increasingly on bacterial eukaryote-like Ser/Thr protein kinases (eSTKs). These protein kinases are structurally similar to their eukaryotic counterparts. Some eSTKs possess additional domains such as extracellular PASTA domains that were discovered in a variety of gram-positive bacteria. It has been proved that these domains can act as sensors for unlinked peptidoglycan fragments. However, majority of environmental signal molecules still remains unknown. eSTKs phosphorylate a broad spectrum of substrates including proteins involved in various cell processes such as virulence, cell wall biosynthesis, cell division, and central and secondary metabolism. Cross talk between eSTKs and two component systems also occurs. In this thesis, the current knowledge about eSTKs and their significant substrates in different bacterial species is discussed.
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Analysis of essentiality of glmM gene coding for phosphoglucosamine mutase of Streptococcus pneumoniae.
Krupička, Jiří ; Branny, Pavel (advisor) ; Čáp, Michal (referee)
Phosphoglucosamine mutase (GlmM) is an enzyme of bacterial cell wall biosynthesis. The main aim of this thesis was to find out, whether gene glmM is essential for viability of Streptococcus pneumoniae. Therefore, we prepared merodiploid strain containing two copies of glmM; the genomic gene and ectopic copy under control of zinc inducible promoter. Subsequently, depletion strain was prepared by deletion of genomic copy of glmM. This strain was further used for analysis of viability and phenotype features in the medium containing various concentrations of zinc ions, an inducer of ectopic glmM expression. We found out, that the viability of this strain was strictly dependent on the concentration of inducer and further, that depletion of GlmM resulted in remarkable morphological defects. The rescue of mutant strain was observed after addition of inducer up to the level of the control sample. These results have provided the evidence of glmM essentiality for S. pneumoniae viability. Furthermore, we analyzed, whether phosphorylation of key amino acid residues, S99 and S101, is essential for GlmM functionality. Four different strains were prepared by means of site-directed mutagenesis expressing glmM with substitutions of key serine residues for alanine or glutamic acid. Since deletion of chromosomal locus in...
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|
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Non-conventional bacterial signaling pathways
Krupička, Jiří ; Branny, Pavel (advisor) ; Beranová, Jana (referee)
Two component systems were traditionally considered as main phosphorylation systems of bacteria involved in cell signalling. Recently, attention focuses increasingly on bacterial eukaryote-like Ser/Thr protein kinases (eSTKs). These protein kinases are structurally similar to their eukaryotic counterparts. Some eSTKs possess additional domains such as extracellular PASTA domains that were discovered in a variety of gram-positive bacteria. It has been proved that these domains can act as sensors for unlinked peptidoglycan fragments. However, majority of environmental signal molecules still remains unknown. eSTKs phosphorylate a broad spectrum of substrates including proteins involved in various cell processes such as virulence, cell wall biosynthesis, cell division, and central and secondary metabolism. Cross talk between eSTKs and two component systems also occurs. In this thesis, the current knowledge about eSTKs and their significant substrates in different bacterial species is discussed.
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