Abstract
To investigate the general radiation-resistant mechanisms of bacteria, bioinformatic method was employed to predict highly expressed genes for four radiation-resistant bacteria, i.e. Deinococcus geothermalis (D. geo), Deinococcus radiodurans (D. rad), Kineococcus radiotolerans (K. rad) and Rubrobacter xylanophilus (R. xyl). It is revealed that most of the three reference gene sets, i.e. ribosomal proteins, transcription factors and major chaperones, are generally highly expressed in the four bacteria. Recombinase A (recA), a key enzyme in recombinational repair, is predicted to be highly or marginally highly expressed in the four bacteria. However, most proteins associated with other repair systems show low expression levels. Some genes participating in 'information storage and processing,' 'cellular processes and signaling' and 'metabolism' are among the top twenty predicted highly expressed (PHX) genes in the four genomes. Many antioxidant enzymes and proteases are commonly highly expressed in the four bacteria, indicating that these enzymes play important roles in resisting irradiation. Finally, a number of 'hypothetical genes' are among the top twenty PHX genes in each genome, some of them might contribute vitally to resist irradiation. Some of the prediction results are supported by experimental evidence. All the above information not only helps to understand the radiation-resistant mechanisms but also provides clues for identifying new radiation-resistant genes from these bacteria.
Highlights
Radiation-resistant bacteria can withstand desiccation and many kinds of radiations such as ultraviolet light (UV), Hg(II), U(VI), Cr(VI)-ionizing radiations (IR), Co-gamma and UV-gamma radiations.[1,2,3,4,5] Unraveling the radiation-resistant mechanisms is an intriguing topic in current life sciences
The percentage of predicted highly expressed (PHX) genes account for 9.6% to 14.1% of all the genes in the four radiation-resistant bacteria, and 19.1%∼31.2% of the PHX genes are function-unknown ‘hypothetical genes’
It is presumed that other proteins involved in DNA repair processes should be highly expressed, whereas the prediction result is much different from our speculation. Both Karlin et al’s and our analyses showed that most genes involved in direct repair, base excision repair, apurinic/apyrimidinic (AP) endonuclease, mismatch excision repair, nucleotide excision repair, recombinational repair and other repair proteins are not highly expressed
Summary
Radiation-resistant bacteria can withstand desiccation and many kinds of radiations such as ultraviolet light (UV), Hg(II)-, U(VI)-, Cr(VI)-ionizing radiations (IR), Co-gamma and UV-gamma radiations.[1,2,3,4,5] Unraveling the radiation-resistant mechanisms is an intriguing topic in current life sciences. Thanks to the rapid progress in genome sequencing projects, the complete genomes of four radiation-resistant bacteria, i.e. Deinococcus geothermalis DSM 11300 (D. geo),[4] Deinococcus radiodurans R1 (D. rad),[1] Kineococcus radiotolerans SRS30216 (K. rad)[3,5] and Rubrobacter xylanophilus DSM 9941 (R. xyl),[2] have been sequenced, which provide an unprecedented opportunity for exploring the radiation-resistant mechanisms of these bacteria.
Sign-in/Register to view highlights & summary Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a callDisclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.
