Bacterial chromosome replication initiates by binding of DnaA protein to the origin. DnaA protein is a sequence-specific DNA binding protein, which binds to eight DnaA boxes in the origin. There are also DnaA boxes on the datA region, which can influence the replication initiation through different binding affinity with DnaA protein. 1.1 Experiment of Molecular Biology In order to characterize the influence of some DnaA boxes of datA region, we chose a 597bp of the datA region to analyze for DnaA protein binding. There are two 0 misfit DnaA boxes in this part separated by 152bp. We analysed the whole region as well as separated it in parts to find the relationship of different DnaA boxes for efficient titration of DnaA proteins. It shows that the two 0 misfit boxes need to cooperate both with each other and with other boxesfor good titration. It seems that the two 1 misfit boxes located along this region should play an important role. 1.2 Sequence Analysis The sequence analysis of the origin for E. coli, Salmonella typhimurium, Shigella flexneri, Yersinia pestis, Vibrio Cholerae, shows that the high affinity DnaA boxes, R1, R2 and R4 are located in the same position of the origin, while low affinity DnaA boxes, R3 and M are located in the same position of the origin except the bacterium, Yersinia pestis. The origin of Yersinia pestis contains one more high affinity DnaA box that overlapping with R1. The sequence analysis of the datA locus for some bacteria shows that two high affinity DnaA boxes are located in the same position of datA region, while a few low affinity DnaA boxes are located between these two high affinity DnaA boxes. A low affinity DnaA box is close to the 0 misffit DnaA box with the same direction and the other low affinity DnaA box is close to the other 0 misfit DnaA box with the opposite direction.
|Uddannelser||Molekylærbiologi, (Bachelor/kandidatuddannelse) Bachelor el. kandidat|
|Udgivelsesdato||29 jun. 2007|