Past Research

RecA protein assures fidelity of DNA repair and genome stability in Deinococcus radiodurans.

RecA protein assures fidelity of DNA repair and genome stability in Deinococcus radiodurans.
Deinococcus radiodurans is one of the most radiation-resistant organisms known. It can repair hundreds of radiation-induced double-strand DNA breaks without loss of viability. Genome reassembly in heavily irradiated D. radiodurans is considered to be an error-free process since no genome rearrangements were detected after post-irradiation repair. Here, we describe for the first time conditions that frequently cause erroneous chromosomal assemblies.

Protein damage and death by radiation in Escherichia coli and Deinococcus radiodurans.

Protein damage and death by radiation in Escherichia coli and Deinococcus radiodurans.
Deinococcus radiodurans is among a small number of bacterial species that are extremely resistant to ionizing radiation, UV light, toxic chemicals, and desiccation. We measured proteome oxidation (i.e., protein carbonylation, PC) in D. radiodurans as well as in standard and evolved resistant strains of Escherichia coli exposed to ionizing radiation or UVC light and found a consistent correlation with cell killing. The unique quantitative relationship between incurred PC and cell death holds over the entire range of killing for all tested bacteria and for both lethal agents, meaning that both bacterial species are equally sensitive to PC.

Unstructured hydrophilic sequences in prokaryotic proteomes correlate with dehydration tolerance and host association.

Unstructured hydrophilic sequences in prokaryotic proteomes correlate with dehydration tolerance and host association.
Here, we explore possible hallmarks of prokaryotic desiccation tolerance in their proteomes. The content of unstructured, low complexity (LC) regions was analyzed in a total of 460 bacterial and archaeal proteomes. It appears that species endowed with proteomes abundant in unstructured hydrophilic LC regions are desiccation-tolerant or sporulating bacteria, halophilic archaea and bacteria, or host-associated species.

Read all Past Researches

Greatest quotes

Science is facts; just as houses are made of stones, so is science made of facts; but a pile of stones is not a house and a collection of facts is not necessarily science.

- Henri Poincare -

No flash player!

It looks like you don't have flash player installed. Click here to go to Macromedia download page.

RecA protein assures fidelity of DNA repair and genome stability in Deinococcus radiodurans.

 
 
 
 
 
DNA Repair (Amst). 2010 Nov 10;9(11):1151-61.

 

Source

Department of Molecular Biology, Ruđer Bošković Institute, Zagreb, Croatia.

Abstract

Deinococcus radiodurans is one of the most radiation-resistant organisms known. It can repair hundreds of radiation-induced double-strand DNA breaks without loss of viability. Genome reassembly in heavily irradiated D. radiodurans is considered to be an error-free process since no genome rearrangements were detected after post-irradiation repair. Here, we describe for the first time conditions that frequently cause erroneous chromosomal assemblies. Gross chromosomal rearrangements have been detected in recA mutant cells that survived exposure to 5kGy γ-radiation. The recA mutants are prone also to spontaneous DNA rearrangements during normal exponential growth. Some insertion sequences have been identified as dispersed genomic homology blocks that can mediate DNA rearrangements. Whereas the wild-type D. radiodurans appears to repair accurately its genome shattered by 5kGy γ-radiation, extremely high γ-doses, e.g., 25kGy, produce frequent genome rearrangements among survivors. Our results show that the RecA protein is quintessential for the fidelity of repair of both spontaneous and γ-radiation-induced DNA breaks and, consequently, for genome stability in D. radiodurans. The mechanisms of decreased genome stability in the absence of RecA are discussed.

Copyright © 2010 Elsevier B.V. All rights reserved.

PMID:
20817622
[PubMed - indexed for MEDLINE]
PDF format soon - Past Research under construction

Homepage Homepage English English Français Français Hrvatski Hrvatski Facebook Facebook

Miroslav Radman - Molecular Biology and Genetics Scientist