“Clever” DNA may help bacteria survive and How DNA is “edited” to correct genetic diseases

“Clever” DNA may help bacteria survive and How DNA is “edited” to

correct genetic diseases.Carolina Carvajal Miranda

Medicine StudentUniversidad Pontificia Bolivariana

Medellín

FOLDING

Molecular biology

Medical student 3° Semester

Teacher Lina Maria Martinez. S

July 28, 2014Medellin, Colombia

Bibliography

Medical Utility

With the knolege and the investigation studies of the DNA structure, scientists can now aproach certain mecanisms in a large form.The change in DNA structure can now be the key phenomenon that will allow us to understand how certain bacterias can become active when transfered from a specific enviroment to the human body, and even, in some cases, become more eficient in their reproduction and survival mecanisms.Also, the discovery of specific funtions of some enzyms that can edit and restore genes can take us closer to cure and treat genetic diseases and gene mutation alterations in order to help patients with severe medical conditions.

Carolina Carvajal Miranda

DNA Estructure

• Mark D. Szczelkuna, Maria S. Tikhomirovab, Tomas Sinkunasd, Giedrius Gasiunasd, Tautvydas Karvelisd, Patrizia Pscherac, Virginijus Siksnysd and Ralf Seidel. Direct observation of R-loop formation by single RNA-guided Cas9 and Cascade effector complexes. PNAS, May 2014

• Monash University. "'Clever' DNA may help bacteria survive." ScienceDaily. ScienceDaily, 4 June 2014. <www.sciencedaily.com/releases/2014/06/140604105536.htm>.

FOLDING

How DNA is 'edited' to correct genetic diseases

An international team of scientists at the Universities of Bristol, Münster and the Lithuanian Institute of Biotechnology observed the mecanisms by which a type of enzymes called CRISPR bind and alter the structure of DNA. This discovery can now help to identify how this genome editing tools work and how they can be used to correct genetic diseases in humans. These enzymes are believed to target a single combination of letters within the three billion base pairs of the DNA molecule. The targeting process requires the CRISPR enzyme to pull apart the DNA strands and insert in them a similar RNA to form a sequence-specific structure called an 'R-loop'. This single molecule assays can helped understand the influence of DNA sequences on R-loop formation. “In the future this may help in the rational re-engineering of CRISPR enzymes to increase their accuracy and minimise off-target effects. This will be vital if we are to ultimately apply these tools to correct

genetic diseases in patients."

 'Clever' DNA may help bacteria survive

A recent research study, published in the journal Proceedings of the Royal Society Interface, has shown that bacterial DNA can change from the regular double helix B form , to the more compact A-DNA form, using a specialized process called the B-A-B transition. This process takes pleace when bacteria is faced with adverse conditions, and doesn’t affect its capacity to function normally and reproduce.Even though there is no biological reason why this mecnism also happends in the human body cells, its recurrence in bacteria results very interesting.The interdisciplinary team at Monash investigated four species of bacteria. They used a carefull process of hydrating and then, dehydrating the cells and studied the results with a infrared based tecnique that detects DNA vibrations. It was found that all species studied underwent the BAB transition. With the first phase complete, now investigations teams can center their attention on working with other conditions such as temperature, pH levels, oxygen, nutrients and antimicrobials and discover if DNA structur changes occur as well.

Introduction

The DNA has the vital job in carrying the genetic code which defines all living organisms. The complex role of the DNA gives us a crucial target point that can be mo-dified and edited to obtain cer- tain caracte- ristics. The discovery of bacteria that can reshape their DNA to survive dehydration and other extreme conditions, or the capacity of certain enzymes to edit specific secuences of DNA, gives us a solid base to secure the fact that variability in DNA can complitly change the course of the human body responce mecanisms.

I think this discovery brings us a step foward in the understanding of how enzymes can edit and modify specific secuences of DNA, bringing us closer in treating genetic deseases.

In my opinion, this research can now explain how certain microorganisms can develop extreme resistance to adverce conditions, and later on, help us develop a more specialized form of treatment to attack infectant bacteria that survive using this type mecanisms.

OBSERVATION

OBSERVATION

INTRODUCTION

• Bacteria can reshape their DNA to survive dehydration.

• Understanding how enzymes “edit” genes, paving the way for correcting genetic diseases in patients.

“Clever” DNA may help bacteria survive (ScienceDaily, 4 June 2014 )

Bacterial DNA can change from B-DNA (double helix) , to the more compact A-DNA form, when exposed to adverse conditions such as

dehydration.

“Clever” DNA may help bacteria survive(ScienceDaily, 4 June 2014 )

B-A-B transition allows

structure change in response to environmental variation.

No impact on the ability to function and reproduce.

Unique structural alteration that generates the B-DNA change to A-DNA, and then revert back to its original B-DNA form.

"Our findings may be important in understanding how dormant bacteria that are transferred from dry surfaces may become active and reproduce in the human body,” Associate Professor Wood said.

“Clever” DNA may help bacteria survive (ScienceDaily, 4 June 2014 )

“Clever” DNA may help bacteria survive (ScienceDaily, 4 June 2014 )

B FORM

Bacteria can survive by adopting the A-DNA form after the majority of water is removed.

A FORM

Dyhadration

“Clever” DNA may help bacteria survive

(ScienceDaily, 4 June 2014 )

Infrared based tecnique detects DNA vibrations.

OBSERVATION

In my opinion, this research can now explain how certain microorganisms can develop extreme resistance to adverse conditions, and later on, help us develop a more specialized form of treatment to attack infectant bacteria that survive using this type of mecanisms.

How DNA is “edited” to correct genetic diseases  

Enzymes “edit” genes paving the way for correcting genetic diseases in patients.

CRISPR enzymes (Cas9) can be used to edit the human genome.

(ScienceDaily, 26 May 2014)

The targeting process requires the CRISPR enzymes to pull apart the DNA strands and then insert the RNA to produce a specific sequence structure called an 'R-loop'.

How DNA is 'edited' to correct genetic diseases

ScienceDaily, 26 May 2014)

How DNA is 'edited' to correct genetic diseases

DNA sequence influences R-loop formation.

Re-engineering of CRISPR enzymes to increase accuracy and minimize off-target effects.

ScienceDaily, 26 May 2014)

Correct genetic diseases in patients.

OBSERVATION

I think this discovery brings us a step foward in the understanding of how enzymes can edit and modify specific secuences of DNA, bringing us closer in treating genetic diseases .

MEDICAL UTILITY

MEDICAL UTILITY “Clever” DNA may help bacteria survive

• The discovery of the changes in DNA structure under extreme circumstances is a key point in the future development of specific treatments for bacterial infections that are dificult to deal with.

• It may also help us understand specific mecanisms that microorganisms use and identify key factors in their survival.

• Lastly, if biological proof of this mecanisms can be found in the human body cells it may be a whole new starting point for scientists in the treatment of diseases that put cells under temperature, pH levels, oxygen, nutrients and antimicrobial stress.

MEDICAL UTILITY“Clever” DNA may help bacteria survive

MEDICAL UTILITY How DNA is “edited” to correct genetic diseases

• In the future, these studies can be used to engineer enzymes alterating their target points in the human DNA. This will be a vital step in correcting genetic diseases in patients.

BIBLIOGRAPHY

MARTINEZ S., Lina Maria. Biologia molecular. 5. ed. Medellin: UPB. Fac. de Medicina,

2009.265 p. Monash University. "'Clever' DNA may help bacteria survive."

ScienceDaily. ScienceDaily, 4 June 2014. <www.sciencedaily.com/releases/2014/06/140604105536.htm>.

Mark D. Szczelkuna, Maria S. Tikhomirovab, Tomas Sinkunasd, Giedrius Gasiunasd, Tautvydas Karvelisd, Patrizia Pscherac, Virginijus Siksnysd and Ralf Seidel. Direct observation of R-loop formation by single RNA-guided Cas9 and Cascade effector complexes. PNAS, May 2014