DNA replication

cellular metabolic process in which a cell duplicates one or more molecules of DNA

thumb|In this diagram of a duplicated chromosome, (2) identifies the centromere—the region that joins the two sister chromatids, or each half of the chromosome. In prophase of mitosis, specialized regions on centromeres called [[kinetochores attach chromosomes to spindle fibers.]]

Enzyme that synthesizes DNA from a nucleic acid template

1976 essay by Richard Dawkins

thumb|upright=1.2|Structure of Escherichia coli|E. coli helicase RuvA (note that the helicase core in RuvAB complex is RuvB and not RuvA and that RuvA alone do not show helicase activity) Helicases are a class of enzymes that are vital to all organisms. Their main function is to unpack an organism's genetic material. Helicases are motor proteins that move directionally along a nucleic double helix, separating the two hybridized nucleic acid strands (hence helic- + -ase), via the energy gained from ATP hydrolysis. There are many helicases, representing the great variety of processes in which st

thumb|Telomerase catalytic subunit TERT of [[Tribolium castaneum (Red flour beetle), bound to putative RNA template and telomeric DNA (PDB 3KYL)]] thumb|A conceptual diagram showing the protein component of telomerase (TERT) in grey and the RNA component (TR) in yellow

short strand of RNA or DNA that serves as a starting point for DNA synthesis

short DNA sequences synthesized discontinuously during DNA replication

experiment

class of enzymes

DNA primase is an enzyme involved in the replication of DNA and is a type of RNA polymerase. Primase catalyzes the synthesis of a short RNA (or DNA in some living organisms) segment called a primer complementary to a ssDNA (single-stranded DNA) template. After this elongation, the RNA piece is removed by a 5' to 3' exonuclease and refilled with DNA.

DNA topoisomerases (or topoisomerases) are enzymes that catalyze changes in the topological state of DNA, interconverting relaxed and supercoiled forms, linked (catenated) and unlinked species, and knotted and unknotted DNA. Topological issues in DNA arise due to the intertwined nature of its double-helical structure, which, for example, can lead to overwinding of the DNA duplex during DNA replication and transcription. If left unchanged, this torsion would eventually stop the DNA or RNA polymerases involved in these processes from continuing along the DNA helix. A second topological challenge

class of enzymes

sequence in a genome at which replication is initiated

single tube technique for the amplification of DNA

thumb|600px|right|A representation of the structures of the replisome during DNA replication The replisome is a complex molecular machine that carries out replication of DNA. The replisome first unwinds double stranded DNA into two single strands. For each of the resulting single strands, a new complementary sequence of DNA is synthesized. The total result is formation of two new double stranded DNA sequences that are exact copies of the original double stranded DNA sequence.

mammalian protein found in Homo sapiens

mechanism of DNA Replication, how dose DNA Replicate

mammalian protein found in Homo sapiens

protein complex which is capable of increasing the processivity of nucleotide polymerization by DNA polymerase as a part of DNA replication

unit of DNA that replicates from a single origin

large protein fragment

proteins that have DNA-binding domains and thus have a specific or general affinity for single- or double-stranded DNA

complex that contains 10 different types of subunits

family of enzymes

correction of replication errors by DNA polymerase using a 3'-5' exonuclease activity.

class of enzymes

enzyme complex

family of proteins

process in which genetic material, in the form of chromosomes, is organized into specific structures

DnaA is a protein that activates initiation of DNA replication in bacteria. Based on the Replicon Model, a positively active initiator molecule contacts with a particular spot on a circular chromosome called the replicator to start DNA replication. It is a replication initiation factor which promotes the unwinding of DNA at oriC. The DnaA proteins found in all bacteria engage with the DnaA boxes to start chromosomal replication. The onset of the initiation phase of DNA replication is determined by the concentration of DnaA. DnaA accumulates during growth and then triggers the initiation of rep

In molecular biology and biochemistry, processivity is an enzyme's ability to catalyze "consecutive reactions without releasing its substrate".

DNA synthesis technique

Protein complex formed during initiation of DNA replication

XPB (xeroderma pigmentosum type B) is an ATP-dependent DNA helicase in humans that is a part of the TFIIH transcription factor complex.

class of enzymes

InterPro Family

complex that loads the DNA polymerase processivity factor proliferating cell nuclear antigen (PCNA) onto DNA, thereby permitting processive DNA synthesis catalyzed by DNA polymerase. In eukaryotes the complex consists of five polypeptides

protein-coding gene in the species Homo sapiens

synthesis of DNA

group of protein complexes

DNA polymerase subunit gamma (POLG or POLG1) is an enzyme that in humans is encoded by the POLG gene. Mitochondrial DNA polymerase is heterotrimeric, consisting of a homodimer of accessory subunits plus a catalytic subunit. The protein encoded by this gene is the catalytic subunit of mitochondrial DNA polymerase. Defects in this gene are a cause of progressive external ophthalmoplegia with mitochondrial DNA deletions 1 (PEOA1), sensory ataxic neuropathy dysarthria and ophthalmoparesis (SANDO), Alpers-Huttenlocher syndrome (AHS), and mitochondrial neurogastrointestinal encephalopathy syndrome (

DNA Replication in Prokaryotes

DnaG is a bacterial DNA primase and is encoded by the dnaG gene. The enzyme DnaG, and any other DNA primase, synthesizes short strands of RNA known as oligonucleotides during DNA replication. These oligonucleotides are known as primers because they act as a starting point for DNA synthesis. DnaG catalyzes the synthesis of oligonucleotides that are 10 to 60 nucleotides (the fundamental unit of DNA and RNA) long, however most of the oligonucleotides synthesized are 11 nucleotides. These RNA oligonucleotides serve as primers, or starting points, for DNA synthesis by bacterial DNA polymerase III (

universally accepted notation uses the Roman characters G, C, A, and T, to represent the four nucleotides commonly found in DNA

family of protein complexes

InterPro Family

DNA Replication in Eukaryotes

Type of non-linear DNA replication

CKLF-like MARVEL transmembrane domain-containing protein 3 (i.e. CMTM3), also termed chemokine-like factor superfamily 3 (i.e. CKLFSF3), is a member of the CKLF-like MARVEL transmembrane domain-containing family (i.e. CMTM) of proteins. In humans, CMTM2 protein is encoded by the CMTM3 gene located in band 22.1 on the long (i.e. "q") arm of chromosome 16. This protein is expressed in a wide range of tissues, including fetal tissues. It is highly expressed in the male reproductive system, particularly testicular tissues and may play a role in the development of this tissue. It is also highly exp

TIMELESS-interacting protein (TIPIN) is a protein that in humans is encoded by the TIPIN gene.