Meeting Abstract
P3-108 - RVT function in bacterium, Herpetosiphon aurantiacus, related to survival in iron-rich environments Urban, RL*; Barnard-Pratt, DD; Yushenova, IA; Arkhipova, IR; Butler University, Indianapolis IN; University of Massachusetts Dartmouth, Dartmouth MA; Josephine Bay Paul Center, Marine Biological Laboratory, Woods Hole MA; Josephine Bay Paul Center, Marine Biological Laboratory, Woods Hole MA rurban@butler.edu
Reverse transcription, a process in which DNA is built from an RNA template, is a specialized function useful for many applications, but found in nature mainly in selfish genetic elements like viruses and transposons. Reverse-transcriptase related (rvt) genes utilize reverse transcription and have been evolutionarily conserved within many taxonomic groups, although patchily, with shared ancestry between both prokaryotes and eukaryotes. While the cellular function of these rvt genes is unknown, rvt gene expression has been found to increase in various transition metals, impacting survival. However, the domain responsible for impacting host survivability is unknown. Initially, the N-terminal coiled-coil domain allowing for the multimerization of RVT proteins was hypothesized to be involved in the interaction with these metal ions. The RVT protein found in Herpetosiphon aurantiacus (HaRVT), a filamentous gliding bacterium, was expected to interact with Fe2+ based on previous gene expression assays. Specific domains of HaRVT were mutagenized to target the domains potentially involved in the response to iron. Escherichia coli was transformed with mutant harvt genes. Transformed E. coli with induced RVT expression were grown on LB-agar plates with increasing concentrations of FeCl2 ranging from 0 mM to 2.5 mM. In addition, H. aurantiacus was grown on milk agar plates supplemented with the same range of FeCl2 concentrations and imaged daily to measure the area of growth. We found that the presence of recombinant HaRVT improves E. coli growth in the presence of iron and allows H. aurantiacus to grow in Fe2+ concentrations up to 1.5 mM. Additionally, the reverse transcriptase domain seems to be more important for HaRVT’s response to Fe2+ than the coiled-coil domain.