Structural and functional characterization of TraI from pKM101 reveals basis for DNA processing
Year: 2023
Type: article
Abstract: Type 4 Secretion Systems (T4SSs) are large and versatile protein machineries that facilitate the spread of antibiotic resistance and other virulence factors via horizontal gene transfer. Conjugative T4SSs depend on relaxases to process the DNA in preparation for transport. TraI from the well-studied conjugative plasmid pKM101 is one such relaxase. Here, we report the crystal structure of the trans-esterase domain of TraI in complex with its substrate oriT DNA, highlighting the conserved DNA binding mechanism of conjugative relaxases. Additionally, we present an apo structure of the trans-esterase domain of TraI that includes most of the flexible thumb region. This allows us for the first time to visualize the large conformational change of the thumb domain upon DNA binding. We also characterize the DNA binding, nicking and religation activity of the trans-esterase domain, helicase domain and full-length TraI. Unlike previous indications in the literature, our results reveal that the TraI trans-esterase domain from pKM101 behaves in a conserved manner with its homologs from the R388 and F plasmids.
Source: Life Science Alliance
Institution: Umeå University
Language: English
Subfield: Genetics
Domain: Life Sciences
Open Access status: gold
Estimated APC paid: $3,500
Awards: G20158103, G208125138, Structural and functional characterisation of Gram-positive Type 4 Secretion Systems, G2339864149, G317939215, G3728818118, G468488144, G5096929151, MAX IV operations – Formas, G5224014036, G5229471624, G594270511, G6384134325, G712881263, MAX IV operations 2019-2021, G8674945231
OpenAlex ID: W4317548989