Eukaryotic Chromosome DNA Replication Where, When, and How

 Eukaryotic Chromosome DNA Replication Where, When, and How DNA REPLICATION The concept of DNA replication is proposed by Watson and crick. DNA replication in eukaryotes occurs in three steps initiation, elongation, and termination, which are aided by several enzymes. WHERE Within the nucleus DNA is present in the form of loose structures associated with simple proteins called chromatin.

 Eukaryotic DNA is bound to proteins known as histones to form structure called nucleosomes. ORC plays an important role in DNA replication.in the budding yeast wherever ORC first known it specifically recognizes the 11-bp or 17-bp preserved present in replicator sequence .There are specific chromosomal locations called origins of replications where replication begins. the temporal side of dsDNA where the replication occurs is called a replication fork.

 For example the yeast ORC recognizes DNA through the AT-hook motif present on the ORC4 subunit and preferentially binds adenine/thymine stretches. WHEN Eukaryotic cells have multiple points of origin, and use unidirectional replication within the nucleus of the cell. 

Most of the cell cycle is spent in the interphase. . some domains replicate after s-phase and some before. A protein determines the initiation on the genome. HOW DNA polymerase can not replicate the end of lagging strand because polymerase requires 3 OH end to bind at daughter strand. 

So it require some additional enzymes to perform it. The first step in DNA replication is to unzip the double helix structure of DNA molecule. 

There are multiple origins of replication on the being chromosome, where replication occure. In first step cdc6, cdt1 and MCM2 7protein are sequentially assembled on the chromosome.