National Center for Biotechnology Information (NCBI) Database

Search Keyword

elibrary ToolsPhotos
Journal Club

Ask Experts

Journal Club Pal

What can be presented at Journal Club this week:


Structure of a DNA Glycosylase Searching for Lesions

Anirban Banerjee,1 Webster L. Santos,1 Gregory L. Verdine1,2

DNA glycosylases must interrogate millions of base pairs of undamaged DNA in order to locate and then excise one damaged nucleobase. The nature of this search process remains poorly understood. Here we report the use of disulfide cross-linking (DXL) technology to obtain structures of a bacterial DNA glycosylase, MutM, interrogating the undamaged DNA. These structures, solved to 2.0 angstrom resolution, reveal the nature of the search process: The protein inserts a probe residue into the helical stack and severely buckles the target base pair, which remains intrahelical. MutM therefore actively interrogates the intact DNA helix while searching for damage.

1 Department of Chemistry and Chemical Biology, Harvard University, Cambridge, MA 02138, USA. 2 Department of Molecular and Cellular Biology, Harvard University, Cambridge, MA 02138, USA.



Chromatin remodeling by nucleosome disassembly in vitro.

Lorch Y, Maier-Davis B, Kornberg RD.

The RSC chromatin-remodeling complex completely disassembles a nucleosome in the presence of the histone chaperone Nap1 and ATP. Disassembly occurs in a stepwise manner, with the removal of H2A/H2B dimers, followed by the rest of the histones and the release of naked DNA. RSC and related chromatin-remodeling complexes may be responsible for the removal of promoter nucleosomes during transcriptional activation in vivo.

Department of Structural Biology, Stanford University School of Medicine, Stanford, CA 94305-5126.


DOWNLOAD pre-made presentation (PPT)


FGF-1 and FGF-2 require the cytosolic chaperone Hsp90 for translocation into the cytosol and the cell nucleus.

Wesche J, Malecki J, Wiedlocha A, Skjerpen CS, Claus P, Olsnes S.

Similarly to many protein toxins, the growth factors FGF-1 and FGF-2 translocate from endosomes into the cytosol. It was recently found that certain toxins are dependent on cytosolic Hsp90 for efficient translocation across the endosomal membrane. We therefore investigated the requirement for Hsp90 in FGF translocation. We found that low concentrations of the specific Hsp90 inhibitors, geldanamycin and radicicol, completely blocked the translocation of FGF-1 and FGF-2 to the cytosol and the nucleus. The drugs did not interfere with the initial binding of FGF-1 to the growth factor receptors at the cell-surface or with the subsequent internalization of the growth factors into endosomes. The activation of known signaling cascades down-stream of the growth factor receptors was also not affected by the drugs. The data indicate that the drugs block translocation from endosomes to the cytosol implying that Hsp90 is required for translocation of FGF-1 and FGF-2 across the endosomal membrane.

Department of Biochemistry, The Norwegian Radium Hospital, Oslo 0310.


DOWNLOAD pre-made presentation (PPT)















Science Promotion Website] [ Membership ] [ Donate ] [ Tell Friends] [MyVideoLib] [ Our Button ] [ Links ] [ Contact Us] [ Advertise with SL

Science eBooks] [ e-Tools for Scientists] [ Scientific Photos] [ Antibiotic Solutions ] [ Chemicals Densities] [ OD260 Calculator ] [ Oligonucleotide (Oligo) Calc] [ Molecular Weight Calc] [ Unit Conversion Calc] [ DNA to Protein Translation Calculator] [ GRE Subject Biochemistry, Cell and Molecular Biology] [ Microscope Masters Contest] [ GRE Subject Biochemistry, Cell and Molecular Biology eBooks and Practice Tests] [ PCR (Polymerase Chain Reaction) Troubleshooting, Optimization, Tips and Tricks - A Lab Guide for Beginners and Experts] [