Centre for Biomolecular Sciences
External Seminar Programme 2008-09
Thursday 25th February 2010
CBS II-A150 Lecture Theatre, 13:00-14:00
Prof. Stephen Bell (Oxford University)
DNA replication and Cell Division in the third domain of life
Stephen Bell
Sir William Dunn School of Pathology
Oxford University
In the talk I will describe our studies of Sulfolobus, a hyperthermophilic
crenarchaeal genus. In common with other archaea, they have transcription and
replication machineries that resemble an ancestral form of the eukaryotic
apparatus. The relative simplicity of the archaeal replication machinery has
facilitated the biochemical analyses of replication proteins. Further, although
prokaryotic, Sulfolobus has three replication origins per chromosome and these
fire in all cells. The firing of all three origins occurs within a narrow temporal
window in the archaeal cell cycle, closely following cell division. With regard to
cell division Sulfolobus lacks homologs of the actin and tubulin superfamily and
yet undergoes cell division by a canonical binary fission mechanism. We have
recently identified archaeal orthologs of the eukaryotic ESCRT apparatus as key
components of the cell division apparatus, shedding light on the ancestral role of
this conserved membrane manipulation system.
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Thursday 11th March 2010
CBS II-A150 Lecture Theatre, 13:00-14:00
Dr. Ariel Blocker (Bristol University)
Type III secretion systems: from function to structure to applications
Ariel J. Blocker, Ph.D.
Senior Lecturer in Microbiology
Departments of Cellular & Molecular Medicine and Biochemistry School of
Medical Sciences University of Bristol University
Type III secretion systems (T3SSs) are essential virulence devices for many
gram-negative bacterial pathogens of humans, animals and plants.
They serve to translocate virulence effector proteins directly into eukaryotic host
cells. T3SSs are composed of a large cytoplasmic bulb, containing the export
apparatus, and a transmembrane region into which a needle is embedded,
protruding above the bacterial surface and terminated by a distinct tip. My group
has studied this nanomachine using a variety of cell biological, biochemical and
structural approaches. Our work has led to substantial novel mechanistic insights
into the function of these systems, which we are now using to progress further
and also to develop new prophylactic and therapeutic tools against the bacteria
that carry them.
These may well become new broad-range anti-virulence treatments at a time
when antibiotic resistance continues to spread.
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Wednesday 24th March 2010
CBS II-A150 Lecture Theatre, 13:00-14:00
Prof. Jerry Wells (Wageningen University, Netherlands)
Microbial TLR signalling in the gut and homeostasis
Jerry Wells
Wageningen University, Netherlands
The mucosal surface of the GI tract is in close proximity to the large number of
commensal and symbiotic bacteria and is also the major portal of entry for
pathogens. Innate pattern recognition receptors such as the Toll-like receptors
recognize both pathogens and non-pathogens thus creating a unique regulatory
challenge for the mucosal immune system. The role of Toll-like receptors in the
homeostasis of tolerance and immunity in the gut and evidence for new
homeostatic mechanisms will be presented.
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Wednesday 31st March 2010
CBS II-A150 Lecture Theatre, 13:00-14:00
Prof. Mike Sutcliffe, FRSC (Manchester University)
DNA replication Dynamically-coupled Enzyme Catalysis: Insight from
Simulation
Mike Sutcliffe
School of Chemical Engineering and Analytical Science University of
Manchester
Enzyme catalysis is inherently a dynamic process, with the catalytic step
involving atomic fluctuations which lead to bonds being broken and new ones
formed.
Protein structures determined from X-ray crystallography and NMR
spectroscopy have provided important insight into the form and function of
enzymes, yet they give only brief snapshots into the life of a protein - very little is
known about dynamic processes that trigger catalysis. This presentation will
illustrate how simulation has been used - synergistically with structural and
kinetic studies - to provide an atomistic description of the link between internal
enzyme motions and catalysis.
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