Sherwood Casjens
Professor of Pathology
B.S. Michigan State University
Ph.D. Stanford University
Sherwood Casjens' PubMed Literature Search
Research
This laboratory is studying two areas of prokaryotic molecular biology: (a) the assembly and DNA packaging of dsDNA bacteriophages and (b) chromosome structure and function in Borrelia burgdorferi, the bacteria that causes Lyme disease.
Our work on the bacteriophage problem has focused on phages lambda and P22. These viruses assemble protein precursor particles (the procapsids) first, and then insert the DNA chromosome into these preformed containers. Our work on these phages has concentrated on understanding the translational control of the expression of the genes whose products are involved in these processes and on dissection of the mechanism by which specific DNAs are recognized and inserted into the procapsids. We are using both genetic and biochemical approaches to determine the specific roles of the several proteins involved in the DNA packaging process.
The second area of study is focused on the genome of the Lyme disease spirochete. We and others have recently found that members of the Borrelia genus have a linear chromosomes. All other well characterized bacteria have circular chromosomes. We are currently characterizing the chromosome ends, and are interested in the handling of the ends by the replication machinery.
References
1. Casjens S, and Thurman-Commike P (2011) Evolution of mosaic tailed bacteriophage genomes seen through the lens of phage P22 virion assembly. Virology 411:393-415
2. Zhao H, Finch C, Sequeira R, Johnson J, Casjens S, and Tang L (2010) Crystal structure of the DNA-recognition component of the bacterial virus Sf6 genome-packaging machine. Proc Natl Acad Sci USA 107: 1971-1976
3. Stewart C, Houtz J, Smith A, Ford M, Peebles C, Casjens S, Hatfull G, Hendrix R, Huang W, and Pedulla M (2009) The genome of bacillus subtilis bacteriophage SP01. J Mol Biol 388:48-70
4. Bhardwaj A, Walker-Kopp N, Casjens S, and Cingolani G (2009) An evolutionarily conserved family of virion tail needles related to bacteriophage P22 gp26: correlation between structural stability and length of the a-helical trimeric coiled-coil. J Mol Biol 391:227-245
5. Nemecek D, Lander G, Carragher B, Potter C, Johnson J, Gilcrease E, Casjens S, Thomas G Jr (2008) Assembly architecture of the bacteriopage P22 terminase small subunit. J. Mol. Biol. 383:494-501
6. Casjens S (2008) Diversity among the tailed-phages of the Enterobacteriaceae. Res. Microbiol. 159:340-348
7. Nemecek D, Gilcrease E, Kang S, Prevelige P Jr, Casjens S, Thomas G Jr (2007) Subunit conformations and assembly states of a DNA translocating motor: The terminase of bacteriophage P22. J. Mol. Biol 374:817-836
8. Olia A, Casjens S, Cingolani G (2007) Structure of phage P22 cell envelope penetrating needle. Nature Str. Biol. 14:1221-1226
9. Lander G, Tang L, Casjens S, Gilcrease E, Prevelige P, Poliakov A, Potter C, Carragher B, Johnson J (2006) A protein sensor for headful viral chromosome packaging is activated by spooled dsDNA. Science 312:1791-1795
10. Weigele P, Sampson L, Winn-Stapley D, Casjens S (2005) Molecular genetics of bacteriophage P22 scaffolding protein's functional domains. J. Mol. Biol. 348:831-844
11. Qiu W, Schutzer S, Bruno J, Attie O, Xu J, Dunn J, Fraser C, Casjens S, Luft B (2004) Recombination and plasmid transfer among Borrelia burgdorferi sensu stricto lineages revealed by three-way genome comparisons and multi-locus sequence typing. Proc. Natl. Acad. Sci., USA 101:14150-14155
Updated 6/1/2011
