IUCr Newsletter - Volume 20, Number 4 - (Page 7)
CrysTallograPhiC meeTing rePorTs
Boston, MA, USA, July 2012
taken from aca ReFLexions,
The 2012 Annual Meeting
was held in Boston, Mass., July
28 through August 1. 785 participants presented 258 posters and
294 lectures. Thirty-nine exhibitors participated in the Exhibit Show,
beginning with the Opening Reception on Saturday and running
through Tuesday. Attendees traveled from 30 counties with 23%
coming from outside the USA. Young scientists (students and postdocs) represented 32% of the total meeting attendance. The meeting
was financially supported by 33 organizations whose contributions
were used to support young scientists, speakers and social events.
The meeting began on Saturday with workshops on Modeling
and Refinement of Nanoparticle Structures from Diffraction Data,
Crystallography - World of Wonders, Refmac and Coot, and Structure Refinement and Disorder Modeling with OLEX2 on Saturday.
Five ACA awards were presented at this meeting. The Buerger
Award to John Spence, the Warren Award to Paul Fenter, the Etter
Early Career Award to Emmanuel Skordalakes, the Supper Instrumentation Award to Ron Hamlin, and the Elizabeth Wood Writing Award to Daniel Nocera.
In his Buerger Award lecture TheFuture of Diffraction Physics in
Crystallography, John Spence noted that due to advances in instrumentation, crystallography continues to have
a bright future. He focused upon two discoveries of the last decade
- lensless imaging, pioneered in Janos Kirz’s
group, and the diffractbefore-destroy approach
to outrunning radiation
damage, first suggested
by Solem and demon- John Spence during his Buerger Award lecture.
strated at Flash (the Photo by P. Mueller.
former Tesla Test Facility) in 2006. He reported the newest results
from femtosecond diffraction experiments at XFEL. With lensless
imaging, using oversampled diffraction data, electron density maps
from single particles can now be reconstructed. The group at the
LCLS in Stanford has published several milestone papers using the
diffract-and-destroy method of serial femtosecond crystallography
(SFX). Pulses of X-rays, brief enough to outrun the resolution limiting effects of damage, are generated in a micron sized beam from
high energy electron bunches with frequency 120 Hz and about
1012 hard X-ray photons per pulse. A constantly refreshed supply
of protein nanocrystals flows across the beam in random orientations. By using short pulses instead of freezing, data can be collected
at room temperature for many proteins which fail to grow crystals
large enough for conventional macromolecular crystallography. Instrumentation has been developed by the ASU group (Doak, Weierstall, Fromme, Spence), the Monte-Carlo method for merging
data from size-varying nanocrystals was described in the dissertation
of Rick Kirian, and software was developed by Tom White in the
IUCr Newsletter ♦ Volume 20, Number 4 ♦ 2012
DESY group. SFX milestones include the achievement of atomic
resolution, and new biology elucidated by images of a drug target.
Spence concluded with a review of the rich opportunities for new
experiments in time-resolved structural biology at XFELS, including pump-probe experiments, new solutions to the phase problem,
and snap-shot biochemical dynamics, using correlated fluctuations
in two-dimensional fast WAX patterns. These will be explored at a
Royal Society Workshop on Biology with XFELS in October 2013.
Paul Fenter (ANL), winner of the 2012 ACA Warren Award, described his research on liquid-solid interfaces, and their importance
processes critical to
society. The B.E.
Warren award is
given to recognize
an important recent contribution
to the physics of
solids or liquids.
Because liquidsolid interfaces are George Phillips on the right, presenting the Warren Award
buried beneath a to Paul Fenter. Photo by P. Mueller.
liquid layer that is opaque to surface sensitive structural tools, Paul
and his colleagues developed phase-sensitive X-ray based scattering
techniques to image structures at liquid-solid interfaces. He cited
three examples: imaging of mineral-water interfaces and elementspecific ion distributions at charged interfaces, and direct imaging of
sub-nm lateral topography and structural variations. Connie Rajnak
The X-ray reflection interface microscope (XRIM) images elementary topography on
a solid surface through the use of phase-contrast. The dark lines on the XRIM image
correspond to 0.65 nm highsteps, whose structure is shown(right).
The 2012 Margaret C. Etter Early Career Award was presented
to Emmanuel Skordalakes (Wistar Inst., U. of Pennsylvania) for his
elucidation of structure of telomerase, an RNA dependent DNA
polymerase that stabilizes chromosomes and is commonly over
expressed in age associated disorders. Emmanuel presented structures of telomerase, alone and in complex with cognate RNA and
DNA substrates. He and his colleagues tested hypotheses about
telomerase function with a series
of experiments inspired by the structures. His findings
set the stage for
the design of better therapeutics for
associated with aberrant telomerase
activity Eric MonEmmanuel Skordalakes, at left, accepting the Etter Early
Career Award from Eric Montemayor. Photo by P. Mueller.
Table of Contents for the Digital Edition of IUCr Newsletter - Volume 20, Number 4
IUCr Newsletter - Volume 20, Number 4
Letter from the President
Crystallographic Meeting Reports
Index to Advertisers
Crystallographic Meetings Calendar
IUCr Newsletter - Volume 20, Number 4