Kontrol af kromosomal replikation i Eschericia coli ved overgangen til den stationære vækstfase

Nouralhuda Aqil Mohsen, Joachim Wittrup Højris Jensen, Maryam Ali, Niklas Follend Lauritsen & Theodor Christian Kier

Studenteropgave: Fagmodulprojekt

Abstrakt

DnaA can form a complex, with ATP bound, which can bind to origin of replication (oriC) to initiate chromosome replication. Acetylation of the lysine-residue K178 at the Walker A motif in DnaA inhibits the ability to bind ATP, and indirectly inhibits chromosomal replication. Recently two proteins that actively facilitate the acetylation and deacetylation DnaA have been identified YfiQ and CobB respectively. In this paper, we set out to investigate the physiological changes that might occur in cell size and DNA content of E. coli, with the introduction of mutations in key initiation-control genes by performing flow cytometry. This was to be done, by producing mutant bacteria, where CobB and YfiQ were inactivated and AcP production was inhibited. The PCR product was to be introduced into the cells by electroporation, and grown on kanamycin plates. Unfortunately, we were not successful in producing the mutant bacteria, but we suspect that the inactivation of the initiation-control genes will have an effect on the cell size and DNA content. The goal of the paper was to produce graphs describing the growth rate, size and density over time for the different mutations, to examine whether the mechanisms proposed by Zhang et al. [Nature. DOI: 10.1038/srep30837 (2016)] had real physiological effect on the bacteria.

UddannelserBasis - Naturvidenskabelig Bacheloruddannelse, (Bachelor uddannelse) Basis
SprogDansk
Udgivelsesdato20 dec. 2016
Antal sider38
VejledereOle Skovgaard