prikaz prve stranice dokumenta Mehanizmi regulacije sustava CRISPR-Cas u bakteriji Escherichia coli
Embargo period 2025-01-27
doctoral thesis
Mehanizmi regulacije sustava CRISPR-Cas u bakteriji Escherichia coli
Zagreb: University of Zagreb, Faculty of Science, 2023. urn:nbn:hr:217:557423
Mitić, Damjan
University of Zagreb
Faculty of Science
Department of Biology

Institutional repository: Repository of the Faculty of Science

Cite this document

Mitić, D. (2023). Mehanizmi regulacije sustava CRISPR-Cas u bakteriji Escherichia coli (Doctoral thesis). Zagreb: University of Zagreb, Faculty of Science. Retrieved from https://urn.nsk.hr/urn:nbn:hr:217:557423

Mitić, Damjan. "Mehanizmi regulacije sustava CRISPR-Cas u bakteriji Escherichia coli." Doctoral thesis, University of Zagreb, Faculty of Science, 2023. https://urn.nsk.hr/urn:nbn:hr:217:557423

Mitić, Damjan. "Mehanizmi regulacije sustava CRISPR-Cas u bakteriji Escherichia coli." Doctoral thesis, University of Zagreb, Faculty of Science, 2023. https://urn.nsk.hr/urn:nbn:hr:217:557423

Mitić, D. (2023). 'Mehanizmi regulacije sustava CRISPR-Cas u bakteriji Escherichia coli', Doctoral thesis, University of Zagreb, Faculty of Science, accessed 26 November 2024, https://urn.nsk.hr/urn:nbn:hr:217:557423

Mitić D. Mehanizmi regulacije sustava CRISPR-Cas u bakteriji Escherichia coli [Doctoral thesis]. Zagreb: University of Zagreb, Faculty of Science; 2023 [cited 2024 November 26] Available at: https://urn.nsk.hr/urn:nbn:hr:217:557423

D. Mitić, "Mehanizmi regulacije sustava CRISPR-Cas u bakteriji Escherichia coli", Doctoral thesis, University of Zagreb, Faculty of Science, Zagreb, 2023. Available at: https://urn.nsk.hr/urn:nbn:hr:217:557423

Metadata
TitleMehanizmi regulacije sustava CRISPR-Cas u bakteriji Escherichia coli
Title (english)Mechanisms regulating the CRISPR-Cas system in Escherichia coli
AuthorDamjan Mitić
MentorIvana Ivančić Baće (mentor)
Committee memberNenad Malenica (predsjednik povjerenstva)
Committee memberDavor Zahradka (član povjerenstva)
Committee memberDušica Vujaklija (član povjerenstva)
GranterUniversity of Zagreb
Faculty of Science
(Department of Biology)
Zagreb
Defense date and country2023-01-27, Croatia
Scientific / art field,
discipline and subdiscipline		NATURAL SCIENCES
Biology
Universal decimal classification
(UDC)		577 - Biochemistry. Molecular biology. Biophysics
Abstract
Sustav CRISPR-Cas je adaptivni imunosni sustav za obranu prokariota od stranih genetičkih elemenata. Regulacija sustava CRISPR-Cas u bakteriji E. coli je kompleksna i nije u potpunosti razjašnjena. Poznato je da protein H-NS djeluje na razini transkripcije, šaperon HtpG na razini post-translacije, dok temperatura utječe na aktivnost proteina Cas3 na nepoznati način. U ovom radu su detaljnije istraženi mehanizmi regulacije aktivnosti sustava CRISPR-Cas na razini transkripcije i post-translacije. Praćenjem otpornosti stanica na infekciju fagom λvir i određivanjem količine transkripata gena cas utvrđeno je da protein StpA može inhibirati promotore Pcas8e i anti-Pcas u nedostatku proteina H-NS, te da pojačana ekspresija ili inaktivacija proteaze Lon u mutantu hns aktivira zaštitu od infekcije neovisno o sustavu CRISPR-Cas. Na aktivnost proteina Cas3 utječe ''anti-sense'' mRNA na nepoznat način, dok temperatura uzrokuje alosteričku promjenu konformacije ovog proteina čime se inhibira njegova nukleazna aktivnost. Šaperon HtpG nije utjecao na količine proteina Cas3, već vjerojatno na zauzimanje njegove pravilne konformacije.
Abstract (english)
The CRISPR-Cas system is a prokaryotic adaptive immune system that provides defense against foreign DNA. The regulation of the CRISPR-Cas system in E. coli is complex and not fully understood. The repressor H-NS acts at the transcriptional level, HtpG posttranslationally, while the activity of Cas3 is affected by temperature in an unknown way. The aim of this research was to further elucidate the mechanisms regulating the activity of the CRISPR-Cas system at the transcriptional and post-translational level. Phage sensitivity assays and quantification of cas transcripts showed that StpA can inhibit Pcas8e and anti-Pcas promoters in the absence of H-NS. Overexpression or inactivation of Lon protease in hns mutants provides protection against phage infection independent of CRISPR-Cas. Cas3 protein activity is affected by an "anti-sense" mRNA in an unknown way, while allosteric change in Cas3 structure by temperature inhibits its nuclease activity. HtpG did not affect Cas3 levels, but the acquisition of the correct conformation.
Keywords
Keywords (english)
Languagecroatian
URN:NBNurn:nbn:hr:217:557423
Promotion2023
Study programmeTitle: Biology
Study programme type: university
Study level: postgraduate
Academic / professional title: doktor/doktorica znanosti, područje prirodnih znanosti, polje biologija (doktor/doktorica znanosti, područje prirodnih znanosti, polje biologija)
Type of resourceText
File originBorn digital
Access conditionsEmbargoed access
Embargo expiration date: 2025-01-27
Terms of useLicence In copyright icon
Created on2023-02-02 10:26:08