Which points to the 3 end of a strand of DNA?

Each end of DNA molecule has a number. One end is referred to as 5′ (five prime) and the other end is referred to as 3′ (three prime). The 5′ and 3′ designations refer to the number of carbon atom in a deoxyribose sugar molecule to which a phosphate group bonds.

What are the 3 phases of replication DNA replication?

Replication occurs in three major steps: the opening of the double helix and separation of the DNA strands, the priming of the template strand, and the assembly of the new DNA segment.

Does DNA polymerase bind to the 3 end?

DNA polymerases can only add nucleotides to the 3′ end of an existing DNA strand. (They use the free -OH group found at the 3′ end as a “hook,” adding a nucleotide to this group in the polymerization reaction.)

What are the 4 stages of DNA replication?

• Step 1: Replication Fork Formation. Before DNA can be replicated, the double stranded molecule must be “unzipped” into two single strands.
• Step 2: Primer Binding. The leading strand is the simplest to replicate.
• Step 3: Elongation.
• Step 4: Termination.

What is primase in DNA replication?

Primase is an enzyme that synthesizes short RNA sequences called primers. These primers serve as a starting point for DNA synthesis. Since primase produces RNA molecules, the enzyme is a type of RNA polymerase. It is critical that primers are synthesized by primase before DNA replication can occur.

What are the 3 DNA processes?

DNA replication steps. There are three main steps to DNA replication: initiation, elongation, and termination. In order to fit within a cell’s nucleus, DNA is packed into tightly coiled structures called chromatin, which loosens prior to replication, allowing the cell replication machinery to access the DNA strands.

What is the function of DPS in starved cells?

DNA-binding protein from starved cells (Dps) is expressed in response to oxidative stress and accumulates in starved cells. In vivo, Dps causes less frequent initiations. Biochemically, this protein interacts with the N-terminal region of DnaA and also inhibits the unwinding of oriC.

When does DNA ligation occur with reduced yields?

DNA to AppDNA ligation occurs with reduced yields. Conversion of 5′-phosphates to 5′-adenylates on ssDNA and ssRNA. Can also ligate the 3′ end of RNA or DNA to a 5′-pDNA when annealed to an RNA complement, and the 3′ end of RNA to a 5′-pRNA when annealed to an DNA complement, with reduced efficiency.

How does DPS affect the initiation of DnaA?

In vivo, Dps causes less frequent initiations. Biochemically, this protein interacts with the N-terminal region of DnaA and also inhibits the unwinding of oriC. These results support a model which proposes that Dps acts as a checkpoint during oxidative stress to reduce the frequency of initiation.

How does DPS protect the bacterial chromosome from damage?

Dps is a stress-induced protein that protects the bacterial chromosome from DNA damage by sequestering and oxidizing Fe 2 + [96,97] (reviewed in Refs. [98,99] ). It also inhibits strand opening of oriC in vitro, which correlates with in vivo evidence that Dps reduces the frequency of initiation [93].