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Promoter activity of ORF-less gene cassettes isolated from the oral metagenome

Tansirichaiya, Supathep, Mullany, Peter and Roberts, Adam ORCID: (2019) 'Promoter activity of ORF-less gene cassettes isolated from the oral metagenome'. Scientific Reports, Vol 9, Issue 8388.

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Integrons are genetic elements consisting of a functional platform for recombination and expression of gene cassettes (GCs). GCs usually carry promoter-less open reading frames (ORFs), encoding proteins with various functions including antibiotic resistance. The transcription of GCs relies mainly on a cassette promoter (PC), located upstream of an array of GCs. Some integron GCs, called ORF-less GCs, contain no identifiable ORF with a small number shown to be involved in antisense mRNA mediated gene regulation.

In this study, promoter sequences were identified, using in silico analysis, within GCs PCR amplified from the oral metagenome. The promoter activity of ORF-less GCs was verified by cloning them upstream of a gusA reporter, proving they can function as a promoter, presumably allowing bacteria to adapt to multiple stresses within the complex physico-chemical environment of the human oral cavity. A bi-directional promoter detection system was also developed allowing direct identification of clones with promoter-containing GCs on agar plates. Novel promoter-containing GCs were identified from the human oral metagenomic DNA using this construct, called pBiDiPD.

This is the first demonstration and detection of promoter activity of ORF-less GCs and the development of an agar plate-based detection system will enable similar studies in other environments.

Item Type: Article
Subjects: QU Biochemistry > Genetics > QU 470 Genetic structures
QU Biochemistry > Proteins. Amino Acids. Peptides > QU 55 Proteins
QU Biochemistry > Proteins. Amino Acids. Peptides > QU 58.5 DNA.
QW Microbiology and Immunology > QW 51 Morphology and variability of microorganisms. Microbial genetics.
Faculty: Department: Biological Sciences > Department of Tropical Disease Biology
Digital Object Identifer (DOI):
Depositing User: Stacy Murtagh
Date Deposited: 12 Jun 2019 12:52
Last Modified: 06 Sep 2019 09:34


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