Replication of the E. coli chromosome starts at a particular point, the origin of chromosomal replication...

Replication of the E. coli chromosome starts at a particular point, the origin of chromosomal replication (oriC) and proceeds bidirectionally around the circular chromosome.

A. Describe how the strands at oriC are separated to allow replication of the chromosome.

B. Once the replication is initiated the process of bidirectional semi-discontinuous DNA replication occurs. Describe this process.

Solutions

Expert Solution

A. Once the site of replication is recognised then certain proteins acts and form two Y shaped replication forks which together forms the replication bubble.

The enzyme called helicase binds here and its main function is to move the replication fork forward and it does so by breaking the hydrogen bonds and thus unwinding the dna strands.

Then some single strand binding proteins comes into play and binds to these single strands and it prevents there re winding.

B. The process is called semi discontinous because the DNA polymerase 3 enzyme used in replication in E.coli can replicate the strand which has direction as 3'-5' so but it cannot replicate the other strand called lagging and if it do so the two newly formed strands will bind thus here other enzyme called primase comes into play

Primase makes primers which attach from 3 to 5 end .primese are 5 to 10 nucleotide strands which will be then elingated by DNA polymerase 1 .

So as the leading strand (3'-5') is replicated continously and the lagging strand discontinously ,hence it is called semi continous.

gladiator answered 1 year ago

Next > < Previous

Related Solutions

1) 5pts - Discuss how an E. coli origin of replication is recognized [sequences?], opened [by...

1) 5pts - Discuss how an E. coli origin of replication is recognized [sequences?], opened [by dnaA], and helicase is added – include any important sequences and their roles in the story. How is this origin licensed? 2) Discuss how promoters, enhancers and the TF proteins that interact with them are used in eukaryotic cells to control transcription of housekeeping genes versus cell specific/regulated genes? Be specific about everything’s role – what binds where and does what! A) 4pts -...

Draw a diagram of a genome replication site in E. coli showing the location of the...

Draw a diagram of a genome replication site in E. coli showing the location of the following components: Helicase; single stranded DNA binding protein; primer; DNA polymerase III; Okasaki fragment; leading strand and lagging strand.

1. a.) how long would it take in minutes to replicate the E. coli chromosome if...

1. a.) how long would it take in minutes to replicate the E. coli chromosome if it used unidirectional rather than bidirectional replication? Explain how you calculated this answer. b.) not accounting for individual chromosomes and telomeres, i.e., use genome size, polyerization rate, and number of origins, how long should it take in hours to replicate the diploid human genome? Explain how you calculated this answer. why is this calculated time less than the observed time?

Explain how the replication of the lagging strand occurs in E. coli. Include a description of...

Explain how the replication of the lagging strand occurs in E. coli. Include a description of the role of each of the key enzymes involved.

To study the molecular mechanism of DNA replication, you incubated soluble E. coli extracts with a...

To study the molecular mechanism of DNA replication, you incubated soluble E. coli extracts with a mixture of dATP, dTTP, dGTP, and dCTP, all of which are labeled with the α-phosphate group. After a while, the incubation mixture was treated with trichloroacetic acid, which precipitate the DNA but not the nucleotide or very short oligonucleotides. The precipitate was collected and the extent of the radioactively label nucleotide incorporation into the DNA was determined. a. Would this assay identify DNA? Explain....

Operon. A particular E. Coli strain has a mutation in the operator of the tryptophan operon....

Operon. A particular E. Coli strain has a mutation in the operator of the tryptophan operon. How would you expect it would affect the functioning of the operon and the metabolism of the cells? What would happen if the trp operon had a mutation in the: 1. Promoter region? 2. Repressor gene (domain binding to tryptophan)? 3. Leader sequence TGGTGG? 4. Region 3 of Leader mRNA?

Why is it important to characterize different strains of a particular species? E. coli, for example.

Using Python Suppose a robot starts at the origin and must reach a target point P...

Using Python Suppose a robot starts at the origin and must reach a target point P in the first quadrant of the Cartesian plane. The robot initially moves in a straight line to an intermediate point (x, y) and then turns and travels along a straight line towards the target P. The robot can move anywhere in the first quadrant and along the horizontal and vertical axes except for a circle centered at the point C with radius r. (a)...

Which of the following statements about the general principles of chromosomal DNA replication in bacteria is...

Which of the following statements about the general principles of chromosomal DNA replication in bacteria is FALSE? a. Chromosomal DNA replication is unidirectional and requires a distinct origin for each strand b. Both leading strand and lagging strand are synthesized simultaneously c. The leading strand is replicated continuously; the lagging strand is replicated discontinuously d. DNA or RNA can serve as primers e. It requires the replisome

Which of the following statements is TRUE? E. coli sigma factors all recognize one E. coli...

Which of the following statements is TRUE? E. coli sigma factors all recognize one E. coli gene Prokaryotic mRNAs contain sequences for sigma factor binding mRNA in both E. coli and humans are translated with the same translation machinery E. coli sigma factors all bind to the core RNA polymerase mRNA always contains the nucleotide sequence encoding just one protein

Subjects