prikaz prve stranice dokumenta Utjecaj točkastih mutacija u genu antiCas i proteina HtpG na aktivnost sustava CRISPR-Cas u bakteriji Escherichia coli
Embargo period 2025-02-23
master's thesis
Utjecaj točkastih mutacija u genu antiCas i proteina HtpG na aktivnost sustava CRISPR-Cas u bakteriji Escherichia coli
Zagreb: University of Zagreb, Faculty of Science, 2024. urn:nbn:hr:217:763009
Žagar, Mirta
University of Zagreb
Faculty of Science
Department of Biology

Institutional repository: Repository of the Faculty of Science

Cite this document

Žagar, M. (2024). Utjecaj točkastih mutacija u genu antiCas i proteina HtpG na aktivnost sustava CRISPR-Cas u bakteriji Escherichia coli (Master's thesis). Zagreb: University of Zagreb, Faculty of Science. Retrieved from https://urn.nsk.hr/urn:nbn:hr:217:763009

Žagar, Mirta. "Utjecaj točkastih mutacija u genu antiCas i proteina HtpG na aktivnost sustava CRISPR-Cas u bakteriji Escherichia coli." Master's thesis, University of Zagreb, Faculty of Science, 2024. https://urn.nsk.hr/urn:nbn:hr:217:763009

Žagar, Mirta. "Utjecaj točkastih mutacija u genu antiCas i proteina HtpG na aktivnost sustava CRISPR-Cas u bakteriji Escherichia coli." Master's thesis, University of Zagreb, Faculty of Science, 2024. https://urn.nsk.hr/urn:nbn:hr:217:763009

Žagar, M. (2024). 'Utjecaj točkastih mutacija u genu antiCas i proteina HtpG na aktivnost sustava CRISPR-Cas u bakteriji Escherichia coli', Master's thesis, University of Zagreb, Faculty of Science, accessed 22 November 2024, https://urn.nsk.hr/urn:nbn:hr:217:763009

Žagar M. Utjecaj točkastih mutacija u genu antiCas i proteina HtpG na aktivnost sustava CRISPR-Cas u bakteriji Escherichia coli [Master's thesis]. Zagreb: University of Zagreb, Faculty of Science; 2024 [cited 2024 November 22] Available at: https://urn.nsk.hr/urn:nbn:hr:217:763009

M. Žagar, "Utjecaj točkastih mutacija u genu antiCas i proteina HtpG na aktivnost sustava CRISPR-Cas u bakteriji Escherichia coli", Master's thesis, University of Zagreb, Faculty of Science, Zagreb, 2024. Available at: https://urn.nsk.hr/urn:nbn:hr:217:763009

Metadata
TitleUtjecaj točkastih mutacija u genu antiCas i proteina HtpG na aktivnost sustava CRISPR-Cas u bakteriji Escherichia coli
Title (english)The effects of point mutations in the antiCas gene and the HtpG protein on CRISPR-Cas system activity in Escherichia coli
AuthorMirta Žagar
MentorIvana Ivančić Baće (mentor)
Committee memberIvana Ivančić Baće (predsjednik povjerenstva)
Committee memberTomislav Ivanković (član povjerenstva)
Committee memberNenad Malenica (član povjerenstva)
Committee memberPetra Peharec Štefanić (član povjerenstva)
GranterUniversity of Zagreb
Faculty of Science
(Department of Biology)
Zagreb
Defense date and country2024-02-23, Croatia
Scientific / art field,
discipline and subdiscipline		NATURAL SCIENCES
Biology
Abstract
Sustav CRISPR-Cas je prokariotski adaptivni obrambeni mehanizam protiv stranih genetičkih elemenata kao što su plazmidi i bakteriofagi. Ovaj sustav sastoji se od lokusa CRISPR koji sadrži segmente strane DNA (razmaknice) okružene palindromskim ponavljanjima te pridruženih gena cas koji sudjeluju u svim fazama obrane. Regulacija sustava CRISPR-Cas je kompleksna i nije još u potpunosti razjašnjena, a najviše je istražena u bakteriji Escherichia coli soja K-12. Neki od poznatih regulatora sustava CRISPR-Cas u bakteriji E. coli su šaperon HtpG, transkript antiCas i temperatura. U ovom radu istražen je utjecaj transkripta antiCas i njegovih točkastih mutanata u obrani bakterija od infekcije fagom λvir kada su nadeksprimirani s plazmida na 31°C. Osim toga, istražen je utjecaj nedostatka transkripta antiCas na aktivnost sustava CRISPR-Cas pri infekciji bakterija fagima na temperaturama od 31°C, 34,5°C te 37°C. Dobiveni rezultati ukazuju na negativan utjecaj transkripta antiCas i njegovih mutanata na aktivnost sustava CRISPR-Cas samo kad su eksprimirani u suvišku. Nadalje, pokazano je da transkript antiCas nema utjecaj na temperaturno ovisnu imunost bakterija na infekciju fagima, već da ona ovisi jedino o pomaku aminokiseline Trp-406 u proteinu Cas3.
Abstract (english)
The CRISPR-Cas system is a prokaryotic adaptive defense mechanism against foreign genetic elements such as plasmids and bacteriophages. This system consists of a CRISPR locus containing fragments of foreign DNA (spacers) surrounded by palindromic repeats, and the associated cas genes involved in all phases of defense. The regulation of the CRISPR-Cas system is very complex and not yet fully understood, and it has mainly been studied in the Escherichia coli strain K-12. Some of the known regulators of the CRISPR-Cas system in E. coli are the chaperone HtpG, the antiCas transcript, and temperature. In this study, the influence of the overexpression of the antiCas transcript and its point mutants from the plasmid on the defense of bacteria against λvir infection at 31°C was investigated. Also, the effect of the lack of the antiCas transcript on the activity of the CRISPR-Cas system against phage infection was investigated at temperatures of 31°C, 34.5°C, and 37°C. The obtained results indicate that the antiCas transcript and its mutants have a negative role on the activity of the CRISPR-Cas system only when they are overexpressed. Furthermore, it was shown that the antiCas transcript has no effect on the temperature-dependent immunity of the bacteria against phage infection, but that this depends only on the shift of the amino acid Trp-406 in the Cas3 protein.
Keywords
Keywords (english)
Languagecroatian
URN:NBNurn:nbn:hr:217:763009
Study programmeTitle: Molecular Biology-University graduate programme
Study programme type: university
Study level: graduate
Academic / professional title: sveučilišni/a magistar/magistra molekularne biologije (sveučilišni/a magistar/magistra molekularne biologije)
Type of resourceText
File originBorn digital
Access conditionsEmbargoed access
Embargo expiration date: 2025-02-23
Terms of useLicence In copyright icon
Created on2024-03-06 11:11:55