James B. Courtright

Professor Emeritus


A.B. 1963, Yale University, New Haven, CT
Ph.D. 1967, Johns Hopkins University, Baltimore, MD
Postdoctoral Fellow, Johns Hopkins University, Baltimore, MD

Functional Topology of the Bacterial Chromosome

My research interests are focused on the mechanisms by which the topology of the bacterial chromosome is maintained while the DNA remains active in replication and transcription. Our approach to this has been to identify discrete sequences where the DNA gyrase (topoisomerase II) binds selectively to the E. coli bacterial chromosome. In this context, our focus has been to determine both the location of gyrase binding sites on the chromosome as well as to determine how the dynamics and folding of the chromosome are changed during different conditions of bacterial replication and gene expression. Related experiments have included how different bacterial species DNA and how heterologous plasmid DNAs are packaged and processed in vivo. These studies are showing that there is a primary structural matrix associated with bacterial chromosomes that establishes and maintains a general configuration required for normal gene expression and replication.
In addition, my interest in bacterial chromosomes and their gene products also extends to developing algorithms and computational methods for determining the evolution and relatedness of bacteria and eukaryotes. These approaches have resulted in the identification of proteins whose structure and functions have changed while retaining a core of common polypeptide sequence. The ability of these multifunctional protein derivatives to display appropriate phenotypes can be tested by reintroduction into the bacterial recipients for determination of stability and function.


Selected Publications  

Noda, A., Denor, P.F., Webb, G., Kohara, Y., Ishihama, A., and Courtright, J.B. 1991. Rapid identification of specific genes in E. coli by hybridization to membranes containing the ordered set of phage clones. BioTechniques 10:474-477.

Webb, G., Rohatgi, K., and Courtright, J.B. 1990 Location of gyrA on the physical map of the Escherichia coli chromosome. J. Bacteriol. 172:6617.

Rohatgi, K., and Courtright J. B. 1990 Major changes in the structure and morphology of the bacterial nucleoid after treatment of cells with quinolones. In: New Quinolones. M. Dekker, New York, pp. 317-326.

Courtright J.B., Turowski, D.A., and Sonstein S.A. 1988 Alteration of bacterial DNA structure, gene expression, and plasmid encoded antibiotic resistance following exposure to enoxacin. J. Antimicrob. Chemother. 21 (Suppl. B):1-18.



Biological Sciences Department

Marquette University, Wehr Life Sciences
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P.O. Box 1881
Milwaukee, WI 53201-1881
(414) 288-7355