Scientists build a better DNA molecule

May 27, 2008

Building faultless objects from faulty components may seem like alchemy. Yet scientists from the Weizmann Institute’s Computer Science and Applied Mathematics, and Biological Chemistry Departments have achieved just that, using a mathematical concept called recursion. 'We all use recursion, intuitively, to compose and comprehend sentences like ‘the dog that chases the cat that bit the mouse that ate the cheese that the man dropped is black,’' says Prof. Ehud Shapiro.

Recursion allows long DNA molecules to be composed hierarchically from smaller building blocks. But synthetic DNA building blocks have random errors within their sequence, as do the resulting molecules. Correcting these errors is necessary for the molecules to be useful. Even though the synthetic molecules are error prone, some of them are likely to have long stretches that do not contain any faults.

These stretches of faultless DNA can be identified, extracted, and reused in another round of recursive construction. Starting from longer and more accurate building blocks in this round increases the chances of producing a flawless long DNA molecule.

The team, led by doctoral students Gregory Linshiz and Tuval Ben-Yehezkel under the supervision of Shapiro, found in their experiments that two rounds of recursive construction were enough to produce a flawless target DNA molecule. If need be, however, the error correction procedure could be repeated until the desired molecule is formed.

The team’s research, recently published in the journal Molecular Systems Biology, provides a novel way to construct faultless DNA molecules with greater speed, precision, and ease of combining synthetic and natural DNA fragments than existing methods. 'Synthetic DNA molecules are widely needed in bio-logical and biomedical research, and we hope that their efficient and accurate construction using this recursive process will help to speed up progress in these fields,' says Shapiro.

Source: Weizmann Institute of Science

Explore further: Researchers study vital 'on/off switches' that control when bacteria turn deadly

add to favorites email to friend print save as pdf

Related Stories

Seeing protein synthesis in the field

Sep 08, 2014

(Phys.org) —Caltech researchers have developed a novel way to visualize proteins generated by microorganisms in their natural environment—including the murky waters of Caltech's lily pond, as in this ...

Cellular RNA can template DNA repair in yeast

Sep 03, 2014

The ability to accurately repair DNA damaged by spontaneous errors, oxidation or mutagens is crucial to the survival of cells. This repair is normally accomplished by using an identical or homologous intact ...

Recommended for you

A new quality control pathway in the cell

13 hours ago

Proteins are important building blocks in our cells and each cell contains millions of different protein molecules. They are involved in everything from structural to regulatory aspects in the cell. Proteins are constructed ...

Stem cells use 'first aid kits' to repair damage

16 hours ago

Stem cells hold great promise as a means of repairing cells in conditions such as multiple sclerosis, stroke or injuries of the spinal cord because they have the ability to develop into almost any cell type. ...

User comments : 0