Podjedinica H arhejske RNA-polimeraze: od kloniranja do istraživanja interakcije s atipičnom seril-tRNA-sintetazom

master's thesis

• Title (english): Archaeal RNA polymerase subunit H: from cloning to investigation of interaction with atypical seryl-tRNA synthetase
• Author: Mirela Marasović
• Mentor: Ivana Weygand-Đurašević (mentor)
• Committee member: Ivana Weygand-Đurašević (predsjednik povjerenstva)
• Committee member: Željka Vidaković Cifrek (član povjerenstva)
• Committee member: Ivana Ivančić Baće (član povjerenstva)
• Granter: University of Zagreb; Faculty of Science; (Department of Biology); Zagreb
• Defense date and country: 2011, Croatia
• Scientific / art field, discipline and subdiscipline: NATURAL SCIENCES; Biology

Abstract

Interakcija podjedinice H arhejske RNA-polimeraze (RpoH) i seril-tRNA-sintetaze metanogenog tipa iz arheje Methanothermobacter thermautotrophicus (MtSerRS) detektirana je ranije u laboratoriju sustavom dvaju hibrida. Asocijacija MtSerRS:RpoH vrlo je zanimljiva budući da se radi o proteinima uključenim u proces koji je od vitalne važnosti za život stanice – ekspresiju gena. Funkcija arhejske RNA-polimeraze je transkripcija svih gena, dok MtSerRS aminoacilira tRNASer serinom te na taj način opskrbljuje ribosom supstratima za elongacijsku fazu translacije. U svrhu potvrde stvaranja kompleksa MtSerRS:RpoH tehnikama in vitro, bilo je potrebno pročistiti pojedine proteine u dovoljnim količinama. Zato je gen rpoH umnožen lančanom reakcijom polimeraze i ugrađen u vektor pod kontrolom jakog T7 promotora. Optimiran je sustav za prekomjernu ekspresiju i pročišćavanje RpoH iz bakterije E.coli, a zatim je RpoH pročišćen u preparativnoj količini. Također, prekomjerno je eksprimirana i pročišćena MtSerRS. Interakcija dvaju proteina istražena je gel-retardacijskom elektroforezom i supročišćavanjem kompleksa na koloni. Preliminarni rezultati dali su naznaku stvaranja kompleksa na nativnom gelu, međutim supročišćavanjem kompleksa na koloni asocijacija MtSerRS:RpoH nije detektirana.

Abstract (english)

A yeast two hybrid screen performed earlier in our laboratory revealed interaction of Archaeal RNA polymerase subunit H (RpoH) and methanogenic-type seryl-tRNA synthetase from Archaea Methanothermobacter thermautotrophicus (MtSerRS). Association MtSerRS:RpoH is very interesting since both proteins are involved in a process vital for cell's life – expression of genes. Archaeal RNA polymerase transcribes genes while MtSerRS aminoacylates tRNASer with serine and supplies ribosome with substrates for elongation phase of translation. In order to confirm the formation of MtSerRS:RpoH complex by in vitro methods, it was nessesary to obtain the individual proteins in sufficient amounts. Therefore, rpoH gene was amplified using PCR and cloned in a vector under control of T7 strong promoter. The system for overexpression and purification of RpoH in Escherichia coli was oprimized, and then RpoH was purified for preparative purposes. Also, MtSerRS was overexpressed and purified. The interaction between two proteins was investigated by gel-retardation electrophoresis and pull-down assay. Preliminary results indicate complex formation on native gel, but the association MtSerRS:RpoH was not detected by pull-down assay.

• Keywords: arheje; Methanothermobacter thermautotrophicus; seril-tRNA-sintetaza metanogenog tipa; podjedinica H arhejske RNA-polimeraze; gel-retardacijska elektroforeza; supročišćavanje kompleksa na koloni
• Keywords (english): Archaea; Methanothermobacter thermautotrophicus; methanogenic-type seryl-tRNA synthetase; RNA polymerase subunit H; gel-retardation electrophoresis; pull-down assay
• Language: croatian
• URN:NBN: urn:nbn:hr:217:026522
• Study programme: Title: Biology; specializations in: Molecular biology; Course: Molecular biology; Study programme type: university; Study level: graduate; Academic / professional title: magistar/magistra biologije (magistar/magistra biologije)
• Type of resource: Text
• File origin: Born digital
• Access conditions: Open access
• Created on: 2018-04-09 08:44:44