Abstract
Upon DNA damage, Sulfolobales exhibit a global gene regulatory response resulting in the expression of DNA transfer and repair proteins and the repression of the cell division machinery. Because the archaeal DNA damage response is still poorly understood, we investigated the promoters of the highly induced ups operon. Ups pili are involved in cellular aggregation and DNA exchange between cells. With LacS reporter gene assays we identified a conserved, non-palindromic hexanucleotide motif upstream of the ups core promoter elements to be essential for promoter activity. Substitution of this cis regulatory motif in the ups promoters resulted in abolishment of cellular aggregation and reduced DNA transfer. By screening the Sulfolobus acidocaldarius genome we identified a total of 214 genes harbouring the hexanucleotide motif in their respective promoter regions. Many of these genes were previously found to be regulated upon UV light treatment. Given the fact that the identified motif is conserved among S. acidocaldarius and Sulfolobus tokodaii promoters, we speculate that a common regulatory mechanism is present in these two species in response to DNA-damaging conditions.
Highlights
The transcription machinery of archaea resembles a simplified version of the eukaryotic RNA polymerase (RNAP) II system, while the mechanisms of transcriptional regulation are more related to bacteria [1,2,3,4,5,6]
In order to characterize the upsX promoter of S. acidocaldarius, we defined the minimal size of the upsX promoter using the reporter plasmid pcMalLacS [36]
Upon DNA damage, Sulfolobales exhibit a distinct transcriptional response resulting in the repression of the DNA replication machinery and the increased expression of oxidative stress enzymes and proteins involved in DNA transfer [29, 30]
Summary
The transcription machinery of archaea resembles a simplified version of the eukaryotic RNA polymerase (RNAP) II system, while the mechanisms of transcriptional regulation are more related to bacteria [1,2,3,4,5,6]. These core elements are recognized by the TATA binding protein (TBP) and transcription factor B (TFB), respectively Binding of these general transcription factors to the promoter subsequently recruits the RNAP to the TSS, thereby forming the pre-initiation complex (PIC) [8,9,10,11,12]. A few DNA regulatory sequences were reported in archaea These include some activating sequences (the ARA box, the ArnR box 1, the ss-LrpB binding site), repressing motifs (the binding site of Phr, TrmB) and the recognition motif of the global regulator TrmBL1 [16, 18, 22,23,24,25,26].
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.
