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Functional study of the putative nucleotidase encoded by spr1057 gene in Streptococcus pneumoniae, a homologue of Escherichia coli protein YjjG
Vacková, Zuzana ; Branny, Pavel (advisor) ; Lichá, Irena (referee)
ANGLICKÝ ABSTRAKT Functional study of the putative nucleotidase encoded by spr1057 gene in Streptococcus pneumoniae, a likely homolog of Escherichia coli protein YjjG. Bacterial cells are constantly exposed to innumerable toxic substances, either in their external environment or by by-products of their own metabolism. For these reasons, the bacterial cells evolved several mechanisms to cope with this challenge. These mechanisms are represented by: blocking the uptake, export by specific transporters as well as specific inactivation of these substance by enzymes. A particular group of these toxic substances are noncanonica nucleotides, which can directly inhibit bacterial cell DNA replication or can result in increased mutation rate. Enzymes recognizing these modified derivatives are known as "house-cleaning" nucleotide phsphateses, which can inactivate the potentially mutagenic nucleotides and prevent their incorporation into DNA and RNA. Some of the "house- cleaning" enzymes belong to a group of haloacid dehalogenase enzymes (haloacid dehalogenase-like hydrolase superfamily), which are found in many bacterial species. This thesis is focused on the function of hypothetical protein Spr1057 of Streptococcus pneumoniae with an unknown function. Sequence comparison revealed that Spr1057 has a significant...
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Study of the unique signaling pathway of Ser/Thr protein kinase StkP and phosphatase PhpP in Streptococcus pneumoniae
Keil, Jan ; Ulrych, Aleš (advisor) ; Bobková, Šárka (referee)
The major human pathogen Streptococcus pneumoniae is a unique model for the study of eukaryotic-type serine/threonine protein kinases and its cognate phosphatases in bacteria, since it encodes only a single signaling pair composed of the StkP protein kinase and PhpP phosphatase. This signaling pair plays a role in several cellular processes, mainly in cell wall biosynthesis and cell division. StkP and PhpP proteins with a pleiotropic effect appear to regulate a complex signaling cascade by phosphorylation of many substrates. However, only a few have been characterized so far. Using MS analysis, we have identified about 90 phosphopeptides that are potential substrates for the StkP kinase and PhpP phosphatase. This diploma thesis is focused on the characterization of the new substrate Spr0929 and its role in pneumococcal physiology. One of the objectives was to investigate cell morphology of strains carrying deletion of the spr0929 gene in different genetic backgrounds. It turned out that the role of Spr0929 in cell morphology is strain specific. The growth curves of strains with this deletion were compared to that of the wild type in various physiological conditions as well. As Spr0929 contains a nucleoid-associated domain called NdpA, determination of its cell localization was an important...
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Functional study of the putative nucleotidase encoded by spr1057 gene in Streptococcus pneumoniae, a homologue of Escherichia coli protein YjjG
Vacková, Zuzana ; Lichá, Irena (referee) ; Branny, Pavel (advisor)
ANGLICKÝ ABSTRAKT Functional study of the putative nucleotidase encoded by spr1057 gene in Streptococcus pneumoniae, a likely homolog of Escherichia coli protein YjjG. Bacterial cells are constantly exposed to innumerable toxic substances, either in their external environment or by by-products of their own metabolism. For these reasons, the bacterial cells evolved several mechanisms to cope with this challenge. These mechanisms are represented by: blocking the uptake, export by specific transporters as well as specific inactivation of these substance by enzymes. A particular group of these toxic substances are noncanonica nucleotides, which can directly inhibit bacterial cell DNA replication or can result in increased mutation rate. Enzymes recognizing these modified derivatives are known as "house-cleaning" nucleotide phsphateses, which can inactivate the potentially mutagenic nucleotides and prevent their incorporation into DNA and RNA. Some of the "house- cleaning" enzymes belong to a group of haloacid dehalogenase enzymes (haloacid dehalogenase-like hydrolase superfamily), which are found in many bacterial species. This thesis is focused on the function of hypothetical protein Spr1057 of Streptococcus pneumoniae with an unknown function. Sequence comparison revealed that Spr1057 has a significant...
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