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master's thesis
Utjecaj temperature i proteina StpA na transkript gena antiCas u zaštiti bakterija Escherichia coli sustavom CRISPR-Cas
Zagreb: University of Zagreb, Faculty of Science, 2023. urn:nbn:hr:217:307365
Knežević, Tea
University of Zagreb
Faculty of Science
Department of Biology

Institutional repository: Repository of the Faculty of Science

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Knežević, T. (2023). Utjecaj temperature i proteina StpA na transkript gena antiCas u zaštiti bakterija Escherichia coli sustavom CRISPR-Cas (Master's thesis). Zagreb: University of Zagreb, Faculty of Science. Retrieved from https://urn.nsk.hr/urn:nbn:hr:217:307365

Knežević, Tea. "Utjecaj temperature i proteina StpA na transkript gena antiCas u zaštiti bakterija Escherichia coli sustavom CRISPR-Cas." Master's thesis, University of Zagreb, Faculty of Science, 2023. https://urn.nsk.hr/urn:nbn:hr:217:307365

Knežević, Tea. "Utjecaj temperature i proteina StpA na transkript gena antiCas u zaštiti bakterija Escherichia coli sustavom CRISPR-Cas." Master's thesis, University of Zagreb, Faculty of Science, 2023. https://urn.nsk.hr/urn:nbn:hr:217:307365

Knežević, T. (2023). 'Utjecaj temperature i proteina StpA na transkript gena antiCas u zaštiti bakterija Escherichia coli sustavom CRISPR-Cas', Master's thesis, University of Zagreb, Faculty of Science, accessed 23 December 2024, https://urn.nsk.hr/urn:nbn:hr:217:307365

Knežević T. Utjecaj temperature i proteina StpA na transkript gena antiCas u zaštiti bakterija Escherichia coli sustavom CRISPR-Cas [Master's thesis]. Zagreb: University of Zagreb, Faculty of Science; 2023 [cited 2024 December 23] Available at: https://urn.nsk.hr/urn:nbn:hr:217:307365

T. Knežević, "Utjecaj temperature i proteina StpA na transkript gena antiCas u zaštiti bakterija Escherichia coli sustavom CRISPR-Cas", Master's thesis, University of Zagreb, Faculty of Science, Zagreb, 2023. Available at: https://urn.nsk.hr/urn:nbn:hr:217:307365

Metadata
TitleUtjecaj temperature i proteina StpA na transkript gena antiCas u zaštiti bakterija Escherichia coli sustavom CRISPR-Cas
Title (english)The effect of the temperature and StpA protein on the antiCas transcript in the CRISPR-Cas mediated protection of Escherichia coli
AuthorTea Knežević
MentorIvana Ivančić Baće (mentor)
Committee memberIvana Ivančić Baće (predsjednik povjerenstva)
Committee memberMirela Sertić Perić (član povjerenstva)
Committee memberNenad Judaš (član povjerenstva)
Committee memberŽeljka Soldin (član povjerenstva)
GranterUniversity of Zagreb
Faculty of Science
(Department of Biology)
Zagreb
Defense date and country2023-09-22, Croatia
Scientific / art field,
discipline and subdiscipline		NATURAL SCIENCES
Biology
Abstract
Mnoge bakterije i većina arheja koriste funkcionalne sustave CRISPR-Cas u obrani protiv strane invazivne DNA. Ekspresija komponenata sustava CRISPR-Cas u E. coli regulirana je s četiri promotora i moguća je samo ako je transkripcijski represor H-NS inaktiviran (Δhns). S promotora anti-Pcas se prepisuje transkript gena antiCas koji nepoznatim mehanizmom utječe na aktivnost sustava CRISPR-Cas. Paralog proteina H-NS, protein StpA u suvišku ukida otpornost na infekciju λvir fagom u Δhns stanicama na 30℃ tako što se ponaša kao dodatni represor. U ovom radu istražena je mogućnost da protein StpA svojom ulogom RNA šaperona utječe na tercijarnu strukturu transkripta antiCas u ovisnosti o temperaturi i time na nukleaznu aktivnost proteina Cas3. Praćenjem otpornosti stanica na infekciju fagom λvir utvrđeno je da suvišak transkripta antiCas pri 31°C inhibira aktivnost CRISPR-Cas sustava neovisno o proteinu StpA, dok je pri suvišku proteina Cas3 na 37°C potreban RNA šaperon StpA kako bi očuvao negativni učinak. Povećana ekspresija transkripta antiCas u mutantima s inducibilnim genima cas uzrokuje lizu stanica i na 31°C i 37°C.
Abstract (english)
Many bacteria and most archaea use functional CRISPR-Cas systems in defense against invading DNA. The expression of CRISPR-Cas system components in E. coli is regulated by four promoters and is only possible if the transcriptional repressor H-NS is inactivated (Δhns). The antiCas gene transcript is transcribed from the anti-Pcas promoter, which affects the activity of the CRISPR-Cas system by an unknown mechanism. A paralog of H-NS protein, StpA protein in excess abolish resistance to λvir phage infection in Δhns cells at 30℃ by acting as an additional repressor. In this paper it was investigated whether the protein StpA, with its role as an RNA chaperone, affects the tertiary structure of the antiCas transcript in temperature dependent manner and consequently affects the nuclease activity of the Cas3 protein. By monitoring the resistance to phage λvir infection, it was determined that the excess of antiCas transcript at 31°C inhibits the activity of the CRISPR-Cas system independently of the StpA protein, while the excess of the Cas3 protein at 37°C requires RNA chaperone StpA to preserve the negative effect. Increased expression of antiCas transcripts in mutants with inducible genes cas causes cell lysis at both 31°C and 37°C.
Keywords
Keywords (english)
Languagecroatian
URN:NBNurn:nbn:hr:217:307365
Study programmeTitle: Integrated undergraduate and graduate university study of Biology and Chemistry Education; specializations in: Integrated undergraduate and graduate university study of Biology and Chemistry Education
Course: Integrated undergraduate and graduate university study of Biology and Chemistry Education
Study programme type: university
Study level: integrated undergraduate and graduate
Academic / professional title: magistar/magistra edukacije biologije i kemije (magistar/magistra edukacije biologije i kemije)
Type of resourceText
File originBorn digital
Access conditionsOpen access
Embargo expiration date: 2024-09-22
Terms of useLicence In copyright icon
Created on2023-10-25 08:55:18