Nancy Trun, Ph.D.Associate Professor
Bayer School of Natural and Environmental Sciences
256 Mellon Hall
Education:Ph.D., Molecular Biology, Princeton University, 1988
B.S., Microbiology, The Ohio State University, 1982
Folding Chromosomes in Bacteria
Chromosomes are long, very thin molecules that must be folded correctly in order to be functional and to fit inside of the cell. Using the model system E. coli, we have identified a family of small DNA binding proteins, called Csp proteins, which help fold the chromosome. E. coli K-12 encodes nine csp genes that are expressed at different times during cell growth. The cell requires the presence of Csp proteins for viability, however no individual Csp has been shown to be essential.
We are currently studying:
1) The biochemistry of CspE to determine nucleic acid substrates and binding requirements.
2) The phenotypes associated with overproduction of CspE to determine the role(s) it plays in vivo.
3) The phenotypes associated with deleting multiple csp genes to determine the minimum number required and the consequences for the cell.
5) Mutants in CspE that distinguish between its roles in gene regulation and the effects it has on DNA topography.
Trun, N.J. and Johnston, D. Folding chromosomes in bacteria: Examining the role of Csp proteins and other small nucleic acid-binding proteins. Current Topics in Develop. Biology 55:173-201, 2003.
Sand, O., Gingras, M., Beck, N., Hall, C., and Trun, N.J. The E. coli chromosome condensing proteins, CrcA, CspE and CrcB can partially substitute for mutations in topoisomerase IV, MukB, Fis, IHF, HU and HNS in vivo. Microbiology 149:2107-2117, 2003.
Trun, N.J. and Marko, J. The architecture of a functional chromosome. ASM News. 64 (5): 276-283, 1998.
Hu, K., Liu, E. Dean, K. Gingras, M., DeGraff, W. and Trun, N.J. Overproduction of three genes leads to camphor resistance and chromosome condensation in E. coli. Genetics 143:1521-1532, 1996.
The novel pedagogy that we are developing, Application-based Service-Learning (ABSL), uses a collaborative and integrated approach to teach scientific research skills to undergraduates in a course setting. Beginning with a community-based problem, students carry out service-learning to understand the problem and its impact on the community. The students apply the scientific method to study a research question posed by the community problem to better understand the problem or to help solve it. During the course of the novel research, students are taught technical writing, laboratory, problem-solving and critical-thinking skills. ABSL was chosen as a Science Education for New Civic Engagement and Responsibilities (SENCER) model course for 2010 (www.sencer.net/Resources/models.cfm) and a featured project of the Critical Thinking Assessment Test (http://www.tntech.edu/cat/links-to-successful-projects/) in 2011 for our students' exceptional gains in critical thinking from an ABSL course.
Information on ABSL can be found on our website: www.ABSLnews.net
Our teaching pedagogoy, ABSL was chosen as a Science Education for New Civic Engagement and Responsibilities (SENCER) model course for 2010 (www.sencer.net/Resources/models.cfm) and a featured project of the Critical Thinking Assessment Test (http://www.tntech.edu/cat/links-to-successful-projects/) in 2011 for our students' exceptional gains in critical thinking from an ABSL course.
Dr. Trun was the recipient of the Duquesne University Presidential Award for Teaching in 2012.
BIOL373W and 573 - Microbiology Superlab IV Spring Semester
BIOL695 - Introduction to Graduate Research Fall Semester
BIOL646 - Advanced Topics in Graduate Biology