Discipline: Biological Sciences
Subcategory: Biochemistry (not Cell and Molecular Biology and Genetics)
Petros Bokretsion - Fisk University
Co-Author(s): Brittni Kelley, UT Knoxville, TN; Dana Franklin, Fisk University, TN; Rekha Pattanayek, Fisk University, TN; Jeremiah Johnson, UT Knoxville, TN; Steven Damo, Fisk University, TN
All organisms require metals for survival. In particular, iron is an essential trace element that is critical for many fundamental biological processes. HeuR regulates iron acquisition from heme in Campylobacter jejuni, a bacterial pathogen that colonizes the gastrointestinal tracts of poultry. Our goal is to understand the molecular basis of HeuR function. Comparative modeling of HeuR suggests the protein is comprised of an N-terminal PAS domain, followed by a linker region and a C-terminal helix-turn-helix DNA binding domain. To characterize HeuR, we expressed the full-length protein recombinantly from E. coli and purified it to homogeneity. Size-exclusion chromatography and dynamic light scattering experiments suggest HeuR forms oligomers. Unfortunately, full-length HeuR protein resisted crystallization for high-resolution structural studies. We attribute this to the flexible linker that connects the PAS and DNA binding domains. We conducted limited proteolysis experiments and identified a stable fragment of the full-length protein that corresponds to the PAS domain. This suggests the PAS domain will be more amenable to crystallization than the full-length protein. Moving forward, we will express and purify the PAS domain of HeuR with an eye toward determining its crystal structure and elucidating its mechanism of action.ern-2018_pb Abstract.doc
Funder Acknowledgement(s): This work is funded by NSF Awards HRD1547757 (CREST) and HRD 1623280 (HBCU-UP).
Faculty Advisor: Steven Damo, email@example.com
Role: Everything associated with the research, such as Expression, Purification, and crystallization of the HeuR protein.