Harvard University - Department of Molecular & Cellular Biology

BRIANA BURTON

Burton
Associate Professor of Molecular and Cellular Biology

Email: bburton@mcb.harvard.edu
Phone: 617-384-6617

Mail: BL 3035
The Biological Labs
16 Divinity Ave
Cambridge, MA  02138

Burton Lab Website
Members of the Burton Lab
List of Publications from PubMed

Courses

MCB 52. Molecular Biology
Catalog Number: 1938  View Course Website
Term: Fall Term 2013-2014.   Credit: Half course.
Instructors: Briana Burton, Thomas Torello
Course Level: Primarily for Undergraduates
Description: An integrated and quantitative introduction to the principles of molecular biology with an emphasis on the experimental underpinning of key concepts. This course covers the biochemistry and structure of DNA; the Central Dogma of molecular biology (DNA replication and repair, transcription and RNA processing, and translation); and an overview of gene regulation and systems biology. The weekly section combines an investigative, discovery-based laboratory research project with a discussion emphasizing problem solving and the scientific method.
Note: This course, when taken for a letter grade, meets the General Education requirement for Science of Living Systems or the Core area requirement for Science B.
Prerequisite(s): Life and Physical Sciences A or Life Sciences 1a; or by permission of the instructor; Life Sciences 1b recommended.
Meetings: M., W., F., at 10, and one laboratory/discussion session weekly.
MCB 330. Mechanisms of DNA Transport Across Membranes
Catalog Number: 7228  View Course Website
Term: Fall Term; Repeated Spring Term 2013-2014.   Credit: Half course.
Instructor: Briana Burton
Course Level: Graduate Course
(View all MCB Courses)

Research

How do cells move one of the largest and most hydrophilic biological molecules across hydrophobic membrane barriers? This is the broad question our laboratory seeks to understand. In bacteria alone, this process is involved in the transfer of antibiotic resistance, spore formation, and proper chromosome segregation during growth. Yet, very little is known about the molecular mechanism of DNA translocation across membranes in any system, as tools to study the mechanism of DNA transporters in their biological context at the membrane have been lacking. We combine in vitro and in vivo biochemistry, microscopy, microbiology and molecular biology to study these DNA transport complexes.

DNA transport during sporulation

Proper chromosome segregation is essential for successful cell division in all organisms. Interestingly, bacterial cells often form a division septum prior to completion of DNA segregation. Sporulating Bacillus subtilis cells provide an extreme example of this phenomenon in that they must transport more than 3 Megabases of a chromosome across a division septum and into the small cellular compartment that will become the spore. SpoIIIE, a member of a large family of bacterial and archeal membrane-bound ATPases (FtsK/SpoIIIE), is required for active transport of the chromosomal DNA at the division septum during sporulation. Using quantitative fluorescence microscopy, and in vivo DNA transport assays to study the oligomeric state and transport properties of the SpoIIIE complex led to the very surprising and novel result that the DNA is transported across two membranes during sporulation. These data predict a new model for DNA transport in which the transmembrane segments of the transporter form linked DNA-conducting channels across the two lipid bilayers of the septum. This system provides a unique opportunity to tackle this interesting phenomenon using complimentary in vivo and in vitro approaches and to address issues which have significant implications for our understanding of how cells efficiently move of large nucleic acids across membranes.

Publications

Marquis KA, Burton BM, Nollmann M, Ptacin JL, Bustamante C, Ben-Yehuda S, Rudner DZ. (2008). SpoIIIE strips proteins off the DNA during chromosome translocation. Genes and Development, 22: 1786-1795.

Burton BM, Marquis KA, Sullivan NL, Rapoport TA, and Rudner DZ. (2007) The ATPase SpoIIIE transports DNA across fused septal membranes during sporulation in Bacillus subtilis. Cell, 131: 1301-1312.

Burton BM and Baker TA. (2005). Remodeling protein complexes: insights from the AAA+ unfoldase ClpX and Mu transposase. Protein Sci. 14:1945-1954. Review.

Sauer RT, Bolon DN, Burton BM, et al. (2004). Sculpting the proteome with AAA(+) proteases and disassembly machines. Cell, 119:9-18. Review.

Burton BM and Baker TA. (2003). Mu Transpososome Architecture Directs Unfolding by ClpX and Proteolysis by ClpXP to Remodel but Not Destroy the Complex. Chem Biol, 10; 463-472.

Burton BM, Williams TL, and Baker TA. (2001). ClpX-Mediated Remodeling of Mu Transpososomes: Selective Unfolding of Subunits Destabilizes the Entire Complex. Molecular Cell, 8; 449-454.

updated: 04/15/2014