Quantity, stability and disparity of ribosomal components in Escherichia coli stationary phase
Date
2023-11-01
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Abstract
Ribosoomid on molekulaarsed kompleksid, mis esinevad kõikides elusorganismides. Ribosoomide ülesandeks eluslooduses on valkude süntees. Valgud on aminohapetest koosnevad polümeerid, mis viivad läbi mitmeid funktsioone bioloogias. Osadel valkudel on katalüütiline aktiivsus, samas teistel on mehhaaniline või struktuurne roll eluslooduses. Huvitaval kombel koosnevad ribosoomid ise valkudest, ergo nende peamise funktsiooni, valgusünteesi produkt, on vajalik nende endi efektiivseks funktsioneerimiseks. R-valkude uurimine on hädavajalik selleks, et mõista molekulaarseid mehhanisme, nagu näiteks antibiootikumide resistentsus, valgusünteesi regulatsioon & kontroll ning ribosoomide kokkupanemine & lagundamine. Selles töös uuriti ribosoomide stabiilsust ning võimekust valke sünteesida statsionaarses kasvufaasis, ennekõike keskendudes r-valkudele. Statsionaarne kasvufaas kirjeldab bakterite elutsükli osa, kus nende kasv on piiratud. Töös on näidatud kuidas mudelorganismi Soolekepikese ribosoomide valguline koostis muutub üleminekul statsionaarsesse kasvufaasi. Huvitaval kombel muutub ribosoomide valguline koostis mitte ainult statsionaarse kasvufaasi alguses, vaid ka statsionaarse kasvufaasi süvenedes. Korrelatsioonis ribosoomi valgulise koostise muutusega, näeme ka ribosoomi valgu sünteesi aktiivsuse muutust statsionaarse kasvufaasi käigus. Lisaks sellele näitame kuidas erineb individuaalsete r-valkude stabiilsus statsionaarses kasvufaasis. Stabiilsuse põhjal jagunevad r-valgud kahte gruppi: 30 stabiilset r-valku ning 21 ebastabiilset r-valku. Saadud tulemused täiendavad meie teadmisi ribosoomide ning nende poolt läbi viidava valgusünteesi kohta mitte-optimaalsetes kasvu tingimustes.
Ribosomes are macromolecular complexes present in every living organism. The function of ribosomes in nature is protein synthesis. Proteins are polymers composing of amino acids, with multiple functions in biology. Some proteins have catalytic activity while others fulfill structural or mechanical roles in nature. Interestingly ribosomes themselves compose of proteins, hence the product of their main function- protein synthesis, is also necessary for their efficient functioning. R-protein research is integral to understand molecular mechanism like antibiotic resistance, protein synthesis regulation, and ribosome assembly or degradation. In this work, we studied ribosome stabilities and translation activity in stationary phase with a focus on r-proteins. In this work we show how ribosome protein composition changes when Escherichia coli cells transition into stationary phase. Interestingly, ribosome protein composition continues to change even in prolonged stationary phase. In correlation with ribosome r-protein composition, we also see increases and decreases in translation activity. Furthermore, individual r-protein stabilities in proteome were determined during stationary phase. Based on their stability r-proteins are divided into two groups: 30 stable r-proteins and 21 short-lived r-proteins. This work complements our knowledge about ribosomes and translation under growth restricting conditions.
Ribosomes are macromolecular complexes present in every living organism. The function of ribosomes in nature is protein synthesis. Proteins are polymers composing of amino acids, with multiple functions in biology. Some proteins have catalytic activity while others fulfill structural or mechanical roles in nature. Interestingly ribosomes themselves compose of proteins, hence the product of their main function- protein synthesis, is also necessary for their efficient functioning. R-protein research is integral to understand molecular mechanism like antibiotic resistance, protein synthesis regulation, and ribosome assembly or degradation. In this work, we studied ribosome stabilities and translation activity in stationary phase with a focus on r-proteins. In this work we show how ribosome protein composition changes when Escherichia coli cells transition into stationary phase. Interestingly, ribosome protein composition continues to change even in prolonged stationary phase. In correlation with ribosome r-protein composition, we also see increases and decreases in translation activity. Furthermore, individual r-protein stabilities in proteome were determined during stationary phase. Based on their stability r-proteins are divided into two groups: 30 stable r-proteins and 21 short-lived r-proteins. This work complements our knowledge about ribosomes and translation under growth restricting conditions.
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Väitekirja elektrooniline versioon ei sisalda publikatsioone
Keywords
ribosomes, ribosome proteins, translation (biol.), Escherichia coli