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Stages of DNA synthesis - Biology


The synthesis of any macromolecule proceeds in three stages: initiation, elongation and termination. During initiation, DNA synthesis begins at a specific site, called an origin of replication. The circular E. coli chromosome has a single origin, called oriC. Termination are the final steps that occur when all or an appropriate portion (replicon, see below) of the chromosome has been replicated.

The primary control of replication is exerted during initiation. This is economical, of course, since little benefit would come from initiating replication that will never be completed. As will be covered later in this chapter, an examination of the DNA structures, proteins and enzymes needed for initiation show that it is highly regulated. Initiation is an active process, requiring the accumulation of ATP-bound DNA binding proteins at a specific site prior to the start of replication. Both the activity of the initiator proteins and the state of covalent modification of the DNA at the origin are part of the control process.


Watch the video: DNA replication and RNA transcription and translation. Khan Academy (November 2021).