Category: Science Highlights

Pilin is the PSI Featured System for April

Researchers with JCSG have recently determined the structure of [TadZ](http://www.pdb.org/pdb/explore/explore.do?structureId=3fkq) bound to ATP. This new PDB along with the structures of other pilins and pilin associated proteins have been chosen as the [PSI featured system of the month](http://sbkb.org/kb/archives.jsp?pageshow=49) for April. Bacteria typically have a large number of genes that encode proteins for the synthesis, localization…
Read more

Model of UV-B sensing by UVR8, a heme-free photoreceptor.

Researchers from [Scripps Research Institute](http://www.scripps.edu/news/press/20120209getzoff.html) and the University of Glasgow have published a detailed molecular model of how UVR8, a unique heme-free plant photoreceptor, senses UV-B light via an intricate interacting mesh of Tryptophan residues positioned at the UVR8 dimer interface which ultimately results in the disruption of a salt bridge and dissociation of the…
Read more

Crystal Structure of Ribosome with Release Factor RF3

Members of the Noller lab recently published a 3.3 Å resolution structure of a complex containing the ribosomal release factor (RF3) locked in its GTP-bound state (mimicked using GDPNP) in association with the *E. coli* 70s ribosome. Crystallographic data for this project was collected at the SIBYLS beamline MX station. > The class II release…
Read more

Flexibility and Mechanism of Ub-PCNA in DNA Repair

Tsutakawa *et al.* have combined solution Small Angle X-ray Scattering (SAXS) data collected at the SIBYLS beamline with computational modeling carried out at Oak Ridge Leadership Computing Facility ( OLCF ) to elucidate new modes of flexibility in a key protein complex (Ubiquitin-PCNA) involved in DNA replication and repair. The work was published in the…
Read more

Insights into Architecture and Mechanism in the Autophagy Pathway

SAXS data collected at the SIBYLS beamline was used in conjunction with high resolution crystals structures to discern details of the unique interaction mode of of these key players in the autophagy pathway. > Atg7 is a noncanonical, homodimeric E1 enzyme that interacts with the noncanonical E2 enzyme, Atg3, to mediate conjugation of the ubiquitin-like…
Read more

Tautomeric form of C•A mismatch is stabilized by polymerase.

Using data collected at the SIBYLS beamline members of the Beese Lab have demonstrated that high fidelity polymerases can stabilize certain tautomeric forms of mismatched base pairs ultimately resulting in incorporation of mutations into the DNA duplex. >Even though high-fidelity polymerases copy DNA with remarkable accuracy, some base-pair mismatches are incorporated at low frequency, leading…
Read more

Structure of XLF-XRCC4 Provides Model for Double Strand Break Repair

DNA double strand break repair via nonhomologous end joining is a critical regulatory function that maintains genomic integrity. One of the major factors involved in this process is the XLF-XRCC4 protein complex. Although mutation of either XLF or XRCC4 leads to defects in break repair, the function of the XLF-XRCC4 complex has remained enigmatic. In…
Read more

SAXS analysis webinar

Special guest speaker, Dina Schneidman from the Sali lab presented a SAXS analysis webinar for members of the NCI program project – Structural Biology of DNA repair (SBDR) on July 14, 2011. She presented how to use the FOXS/FOXS-MES server and an example application. She introduced FOXSDOCK (which is almost ready). Additionally, she showed how…
Read more