New chromosome origin element identified

June 08, 2016

Newcastle University scientists have discovered a new essential sequence within bacterial genomes required for DNA replication - the second ever to be discovered and the first for 30 years.

Publishing today in Nature, the Newcastle team describe how they identified the new site and determined the mechanism by which it promotes DNA duplication.

The "DnaA-trio" is described as a core element of bacterial replication origins and represents a significant advance for scientific understanding.

Origins

In all cells genome duplication requires key proteins called "initiators" to unwind the DNA double helix at specific sites known as "origins".

DNA unwinding provides the replication machinery access to single strands which act as templates for new rounds of DNA synthesis.

While initiators are highly conserved throughout all organisms and well characterised, there is still a lot to learn about "origins".

In fact, within higher organisms such as animals and humans, scientists have yet to define what constitutes an origin.

DnaA-trio

In the paper, the team explain how the novel and essential bacterial replication origin element directs single-strand DNA binding by the master initiator protein DnaA to promote opening of DNA duplex.

They determine that the element is composed of a simple repeating three base pair sequence, which they term the DnaA-trio.

Lead author, Dr Heath Murray a researcher in the Centre for Bacterial Cell Biology at Newcastle University said: "This discovery sheds new light onto a fundamental biological process shared amongst all living organisms, the duplication of genes in order to pass this essential material down to future generations."
-end-
The work was funded by the Biotechnology and Biological Sciences Research Council (BBSRC) and Dr Murray was funded by a Royal Society University Research Fellowship.

The discovery opens the door to the search for enigmatic replication origin elements in higher organisms, such as animals and humans.Reference: The bacterial DnaA-trio replication origin element specifies ssDNA initiator binding. Tomas T. Richardson, Omar Harran, and Heath Murray. Nature. DOI: 10.1038/nature17962

Newcastle University

Related DNA Replication Articles from Brightsurf:

Exercise hormone may modulate genes associated with replication of novel coronavirus
Brazilian researchers observed that in uninfected adipocytes, the hormone irisin altered the expression of genes that regulate ACE-2, which encodes a protein to which the virus binds in order to invade human cells.

Genome guardians stop and reel in DNA to correct replication errors
New research shows how proofreading proteins prevent DNA replication errors by creating an immobile structure that calls more proteins to the site to repair the error.

USC scientists examine the impact of a very specific defect in DNA replication
The new lab study finds an unexpected glitch in a gene that supervises mitosis, one that has important implications for cancer treatment.

Dynamics of DNA replication revealed at the nanoscale
Using super-resolution technology a University of Technology Sydney led team has directly visualised the process of DNA replication in single human cells.

Stitching together the structure of the DNA replication toolbelt
Structural details of an enzyme complex shed light on DNA replication.

Elucidation of mechanisms that coordinate cell memory inheritance with DNA replication
Why normal cells turn into cancer cells? One of the factors is deeply related to the failure of the cell differentiation mechanism called DNA methylation.

Scientists reveal function of histone variant H2A.Z in DNA replication selection
The research published in Nature on Dec. 25th, 2019, led by Dr.

How cells relieve DNA replication stress
IBS scientists revealed that ATAD5 actively deals with replication stress, in addition to its known function to prevent such stressful situations.

Scientists unwind mystery behind DNA replication
The molecules of life are twisted. But how those familiar strands in DNA's double helix manage to replicate without being tangled up has been hard to decipher.

A protein essential for chikungunya virus replication identified
Chikungunya is an infectious disease caused by a mosquito-borne virus transmitted to humans.

Read More: DNA Replication News and DNA Replication Current Events
Brightsurf.com is a participant in the Amazon Services LLC Associates Program, an affiliate advertising program designed to provide a means for sites to earn advertising fees by advertising and linking to Amazon.com.