An ICEBs1-like element may be associated with the extreme radiation and desiccation resistance of Bacillus pumilus SAFR-032 spores
Comparisons of the genomes of Bacillus pumilus SAFR-032 and the closely related type strain, B. pumilus ATCC7061T, exposed an extended region of non-homologous genes. A detailed examination of this region revealed the presence of an ICEBs1-like integrative conjugative element in SAFR-032. A similar element was subsequently located elsewhere in the ATCC7061T genome. A detailed comparison of these elements and the ICEBs1 of B. subtilis revealed extremely rapid flux in gene content, genome organization and sequence similarity. It is not clear if the B. pumilus elements as they are currently structured are functional. However, it is clear that the past involvement of these elements has brought multiple genes of unknown function to the SAFR-032 genome and these genes may be responsible for the rapid evolution that led to the extreme radiation and desiccation resistance of this organism’s spores.
KeywordsGenome analysis Comparative genomics Radiation resistance Planetary protection Integrative conjugative elements
Integrative and conjugative element
Bacillus pumilus strain SAFR-032
Bacillus pumilus ATCC7061T
Conserved hypothetical protein
Gene locus tag number for the type strain B. pumilus ATCC7061T
Gene locus tag number for B. pumilus SAFR-032
This work was supported in part by grants from the Institute of Space Systems Operations at the University of Houston, the Center for Bio-nanotechnology and Environmental Research at Texas Southern University (NASA Cooperative agreement NNX08B4A47A), and the Center for Ribosomal Evolution and Adaptation at the Georgia Institute of Technology (NASA Cooperative Agreement NNA09DA78A).
Conflict of interest
The authors declare that they have no conflict of interest.
All work described in this manuscript was performed in accordance with current laws in the United States of America.
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