Navish Wadhwa: Environmentally regulated self-assembly of the bacterial flagellar motor

Mon, Dec 16, 2019, 12:00 pm
Location: 
Joseph Henry Room Jadwin Hall
Speaker(s): 
Sponsor(s): 
CPBF an NSF PFC

Macromolecular protein complexes perform essential biological functions across life forms. The assembly of such complexes is known to be regulated at the level of gene transcription, but little is known about the factors that control their assembly once the mature protein subunits enter their target space (cytoplasm, membrane, or cell wall). Even less is known about how their assembly is regulated by extracellular signals from the environment. The bacterial flagellar motor is a large macromolecular machine that powers motility in bacteria. The torque-generating stator units of the motor assemble and disassemble in response to changes in external load. We used electrorotation (applying high frequency rotating electric fields) to drive tethered cells forward, which decreases motor load, and measured the resulting stator dynamics. No disassembly occurred while the load remained high, but all of the stator units were released when the load on the motor was reduced by spinning it forward at high speed. When the electrorotation was turned off, so that the load was again high, stator units were recruited, increasing motor speed in a stepwise fashion. A model in which speed affects the binding rate and torque affects the free energy of bound stator units captures the observed stator assembly and disassembly dynamics, providing a quantitative framework for the environmentally regulated self-assembly of a major macromolecular machine.

Navish Wadhwa: Environmentally regulated self-assembly of the bacterial flagellar motor

Mon, Dec 16, 2019, 12:00 pm

Macromolecular protein complexes perform essential biological functions across life forms.

Location: Joseph Henry Room Jadwin Hall

Dmitry Rinberg: TBD

Mon, Jan 27, 2020, 12:00 pm
Location: Joseph Henry Room Jadwin Hall

Sven van Taeffelen: TBD

Mon, Feb 3, 2020, 12:00 pm
Location: Joseph Henry Room Jadwin Hall

Elizabeth Jerison: TBD

Mon, Feb 10, 2020, 12:00 pm
Location: Joseph Henry Room Jadwin Hall

Elizabeth Jerison: Dynamics of adaptive immunity in zebrafish

Mon, Feb 10, 2020, 12:00 pm
Location: Joseph Henry Room Jadwin Hall

Stephanie Palmer: TBD

Mon, Feb 17, 2020, 12:00 pm
Location: Joseph Henry Room Jadwin Hall

Symposia: TBD

Fri, Feb 21, 2020, 9:30 am
Location: The Graduate Center, Room 4102. 365 Fifth Avenue, between 34th and 35th Streets, Manhattan

Andrew York: TBD

Mon, Feb 24, 2020, 12:00 pm
Location: Joseph Henry Room Jadwin Hall

Andreas Gahlman: TBD

Mon, Mar 9, 2020, 12:00 pm
Location: Joseph Henry Room Jadwin Hall

Andreas Gahlmann: TBD

Mon, Mar 9, 2020, 12:00 pm
Location: Joseph Henry Room Jadwin Hall

Symposia: TBD

Fri, Mar 13, 2020, 9:30 am
Location: The Graduate Center. 365 Fifth Avenue, between 34th and 35th Streets, Manhattan

Allan Drummond: TBD

Mon, Mar 16, 2020, 12:00 pm
Location: Joseph Henry Room Jadwin Hall