Main Page

by David Canner
The X-ray structure of HIV-1 protease reveals that it is composed of two symmetrically related subunits which form a tunnel where they meet. This is critical because it contains the active site of the protease, consisting on two Asp-Thr-Gly conserved sequences, making it a member of the aspartyl protease family. The two catalytic Asp's either interact with the incoming water or protonate the carbonyl to make the carbon more electrophilic for the incoming water.

>>> Visit this page >>>

by Eric Martz
A historical review on sculptures and physical models of macromolecules.

>>> Visit this page >>>

IB Tomasic, MC Metcalf, AI Guce, NE Clark, SC Garman. J. Biol. Chem. 2010 doi: 10.1074/jbc.M110.118588
The human lysosomal enzymes α-galactosidase and α-N-acetylgalactosaminidase share 46% amino acid sequence identity and have similar folds. Using a rational protein engineering approach, we interconverted the enzymatic specificity of α-GAL and α-NAGAL. The engineered α-GAL retains the antigenicity but has acquired the enzymatic specificity of α-NAGAL. Conversely, the engineered α-NAGAL retains the antigenicity but has acquired the enzymatic specificity of the α-GAL enzyme. Comparison of the crystal structures of the designed enzyme to the wild-type enzymes shows that active sites superimpose well, indicating success of the rational design. The designed enzymes might be useful as non-immunogenic alternatives in enzyme replacement therapy for treatment of lysosomal storage disorders such as Fabry disease.

>>> Visit this I3DC complement >>>

by Eric Martz
The Ramachandran Principle says that alpha helices, beta strands, and turns are the most likely conformations for a polypeptide chain to adopt, because most other conformations are impossible due to steric collisions between atoms. Check Show Clashes to see where non-bonded atoms are overlapping, and thus in physically impossible positions.

>>> Visit this tutorial >>>