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Hi everyone I need help in correcting the grammar mistakes in my abstract is due Thur.
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DNA replication process needs many factors and enzymes to stabilize and control the separation of a double stranded DNA. An important side within the DNA called an origin of replication, Oric in E. coil, which is first targeted by a replication initiator protein called DnaA that initiate the unwinding. These initiator proteins recruit other proteins to separate the two strands and initiate replication forks. This origin of replication is a 245 bp that contain a 13 mer, an A-T rich sequence, followed by several 9 mer repeat region that contain different affinity binding sites for DnaA proteins. There are five R boxes, three I sites, and one S_M site within the Oric region. (R1, R4, R2) are high affinity sites that can bind Dna-ATP while (R5m, I2, I3, I1, and R3) are low affinity sites that can bind Dna-ADP. To insure a good pre-replication complex formation DnaA should fill the high affinity sites first that cause a drop in the level of FIS, which blocks the binding of DnaA in the low affinity sites, and raise the level of IHF to allow the interaction of DnaA with the low affinity sites and start the unwinding. Our focus in this work is to find the factors that affect the unwinding of DNA, specially the function and the arrangement of the high affinity sites. Here we used transformation method for several plasmids in four different cells, those plasmids are Poc170 which is 3852 bp long and carries replication origins from both pBr322 and Oric and it was used as a control, PTN09 which contains an inactive Oric, PTN04 contains R1 box only, PTN03 contains R2 box only, PDM1 contains R4 box only, and PJT19 that contains both R2 and R4 boxes. The cells we used were a wild type cells, wt W3110, that have a normal Oric and can compete with several plasmid Oric, wt P3478 which is a poly-A strand and contain a point mutation, ∆ Oric W3110 cells which lack Oric site in its chromosome, and ∆ Oric P3278 with poly-A and point mutation in its strand. Our result showed that one R box cannot function alone to initiate replication, although the arrangement of all the R boxes is important for replication process.