Rationale: In this day of exploding bioinformatics information
from genomics and proteomics, it is ever more important to be conversant
with macromolecular three-dimensional structure, and how it relates to
protein and nucleic acid function and rational drug design. This workshop will
enable participants to find published molecular structure data, and visualize
and interpret 3D molecular structure. Participants will be enabled to
incorporate computer visualization of protein, DNA, and RNA into their
teaching and research.
Software: The central tool for this workshop is Protein Explorer
(www.proteinexplorer.org). Protein Explorer is free,
operates on Windows or Macintosh (also
linux), and is much easier to use, yet much
more powerful than RasMol. Protein Explorer has been adopted for visualization
of macromolecular 3D structure by the Protein Data Bank
(www.pdb.org).
Level & Pace: This workshop is designed for
educators and biological scientists familiar with basic biochemistry, but with no
previous molecular visualization software experience.
It progresses rapidly to powerful tools that will be of interest
to researchers, including specialists in protein structure and bioinformatics.
Experienced participants are encouraged to work at their own speed,
ahead of the group -- there is plenty of power in Protein Explorer to discover!
Hyperlinks: To click the hyperlinks below, go to this document on the web,
http://www.umass.edu/molvis/workshop/ubarc01.htm
Tuesday April 24.
Basics.
How to use Protein Explorer to visualize structural features of
proteins and nucleic acids.
Observations may be recorded on a form provided.
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FirstView
- Use of the mouse to rotate the molecule; clicking to identify atoms.
- Identifying and becoming familiar with the computer representations for chains, backbones, disulfide bonds, solvent, and ligands.
QuickViews
- Selecting, emphasizing, and hiding portions of the molecule.
- Zooming, centering.
- Backbone, trace, cartoon, stick, ball and stick, spacefill to van der Waals radii.
- Coloring by element (Corey, Pauling, Koltun color scheme).
- Coloring cartoons by secondary structure.
- Identifying the amino and carboxy termini (5', 3' ends): N->C Rainbow (Group) color scheme.
- Interpreting the distribution of hydrophobic, polar, and charged residues
(Polarity color schemes).
- Potassium channel: 1bl8. Trp prefers lipid-water interface.
- Gramicidin in a lipid bilayer:
bilagram.pdb
- Coloring to distinguish A, T, G, C, U. How to distinguish DNA from RNA.
- Coloring by disorder: temperature factor coloring.
Sequences
- Protein Explorer's Sequence display.
- Insertions and non-physical gaps: 1igt.
- Physical gaps: 2ace, 1fod.
- Microheterogeneity: 1cbn.
- Protein Explorer's clickable Seq3D
- Sequence to 3D structure mapping.
- Finding all instances of one amino acid (e.g. cysteine).
- Selecting and coloring an arbitrary range of residues.
- Free time to review and explore.
Wednesday April 25:
Finding molecules of interest.
Exploring and interpreting their structures.
Animations.
Observations may be recorded on a form provided.
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- Overview of origin, nature, and limitations of molecular structure data (X-ray crystallography,
nuclear magnetic resonance).
- The Protein Data Bank
- Finding molecules of interest.
- Getting information about your molecule.
- Protein Explorer's Molecule Information Window:
- PDB File Header
- Probable Quaternary Structures
- Crystal Contacts
- Model Quality (& examples of errors in published PDB files)
- RCSB's Structure Explorer.
- NCBI Entrez, PubMed
www.ncbi.nlm.nih.gov
- Animations.
- Multiple-model NMR PDB files: simulation of thermal motion.
- Morphs of conformational changes.
- Free time to explore participant's molecules.
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Thursday April 26:
Contact surfaces reveal noncovalent bonds.
Cation-pi interactions and salt bridges.
Coloring a 3D protein by conservation/mutation from a multiple
protein sequence alignment (MSA3D).
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- Contact surfaces. Example: Gal4 contacting DNA (1d66), showing:
- Nonspecific charge interactions at DNA backbone phosphates,
- Sequence specific recognition DNA bases by zinc finger domain of protein,
- Hydrophobic protein-protein interaction.
- Visualizing cation-pi interactions and salt bridges.
- Preferences in Protein Explorer.
- Demonstration of Protein Explorer's MSA3D.
- Building a multiple protein sequence alignment.
- Locating regions of conservation or mutation with
Protein Explorer's MSA3D.
- Free time to review and apply new methods to your molecule.
Friday April 27:
Optional day (attendence not required) for individual work, or topics
chosen by those attending.
Use what you've learned. Possible new topics:
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- Hydrogen bonds.
- The Noncovalent Bond Finder.
- Introduction to using the RasMol/Chime Command Language.
- Building a web page with hyperlinks to Protein Explorer that
prespecify molecules for your teaching or research.
- Ready-to-use tutorials in Chime for teaching
- Rolling probe surfaces and molecular electrostatic potential coloring.
- Searching by structure without reference to sequence:
- Aligning two or more chains or molecules, and how to view the alignment.
- The CE site
cl.sdsc.edu/ce.html
will align any two protein chains quickly and easily
(but hetero atoms are discarded).
- Swiss PDB Viewer
www.expasy.ch/spdbv/mainpage.html
can align anything
(one or more than one chains), selecting any subset of atoms for
the alignment (other atoms following), and retaining hetero
atoms. The results can be saved as a PDB file. It will need
manual editing to separate models with MODEL [N] and ENDMDL
records so that Protein Explorer can distinguish the models.
- Modeling: mutation, homology modeling, crystallographic contacts.
- Building Chime presentation websites.
- Keep in touch!
- Free time for individual work.
Example Molecules: PDB ID Codes
For ready-made tutorials, see the
World Index
by subject/molecule name.
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*Antibody (Fab-lysozyme) 1fdl
*Antibody (intact IgG) 1igt
-
ATP
-Bacteriorhodopsin 1c8r
-Capsid, rhinovirus, intact
rhino-ca
-EF hand, morph
reco_ef2***
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*Hemoglobin, oxy 1hho, 1hho.mmol*
*Hemoglobin, deoxy 2hhd
*Hemoglobin, sickle 1hbs
-Hemolysin ("mushroom") 7ahl
-HIV protease-inhibitor 1ohr
*Major Histocompatibility I (with virus peptide) 2vab
*Major Histocompatibility II (with virus peptide) 1dlh
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-Nucleosome-DNA 1aoi
-Potassium Channel 1bl8
-RNA Polymerase, T7 1qlv
*
SV40 capsid assembly
-T cell receptor 1sbb
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* See ready-to-use tutorial(s) on this molecule at the
World Index.
** Get mmol files from Probable Quaternary Structures,
msd.ebi.ac.uk/Services/Quaternary/quaternary.html
*** Also available on PE's
Animations page.
Collaborations are invited that use
Protein Explorer to display information about macromolecular structure,
particularly information which may be the result of your research.