bioRxiv Science⌕ Search

Biology subjects

Herlihy, A.

Publications and source records attributed to Herlihy, A..

2 recordsLinked to original sources

Understanding the genetic diversity of bacteria isolated from across the Atacama Desert

Despite being one of the driest and harshest deserts on Earth, the Atacama Desert is home to a variety of bacterial life. Microorganisms that reside here may have developed adaptations to help them survive this unique environment. In this study, we used bioinformatic and genetic methods to assess the abundance of phyla that are present in this environment and what types of adaptations individual bacteria have obtained. To assess bacterial diversity, we used 16S rRNA sequencing on soil samples and determined the relative composition of different phyla and archaea at sixteen locations. A selection of eight cultivatable organisms which produce pigments were subjected to whole genome sequencing (WGS). Using these sequences, we screened for stress-tolerance capabilities including pigment production pathways, biofilm-related genes, antibiotic production, and genome stability. We found that all strains we sequenced are predicted to produce bioactive compounds. We also found that the pigments that these bacteria produce have antioxidant, iron and ion chelating, and/or antibiotic properties. This characterization allows us to assess adaptive strategies of bacteria which is important in the fields of agriculture, biotechnology and health.

microbiology↗

STK19 facilitates the clearance of lesion-stalled RNAPII during transcription-coupled DNA repair

Transcription-coupled DNA repair (TCR) removes bulky DNA lesions impeding RNA polymerase II (RNAPII) transcription. Recent studies have outlined the stepwise assembly of TCR factors CSB, CSA, UVSSA, and TFIIH around lesion-stalled RNAPII. However, the mechanism and factors required for the transition to downstream repair steps, including RNAPII removal to provide repair proteins access to the DNA lesion, remain unclear. Here, we identify STK19 as a new TCR factor facilitating this transition. Loss of STK19 does not impact initial TCR complex assembly or RNAPII ubiquitylation but delays lesion-stalled RNAPII clearance, thereby interfering with the downstream repair reaction. Cryo-EM and mutational analysis reveal that STK19 associates with the TCR complex, positioning itself between RNAPII, UVSSA, and CSA. The structural insights and molecular modeling suggest that STK19 positions the ATPase subunits of TFIIH onto DNA in front of RNAPII. Together, these findings provide new insights into the factors and mechanisms required for TCR.

molecular biology↗