Protein Structural Bioinformatics
3-Day Course in 3D Macromolecular Visualization & Analysis with Protein Explorer
Washington University, Saint Louis
Lead Instructor
Eric Martz
(author of Protein Explorer; Prof. Emeritus, Univ. Mass. Amherst; emartz@microbio.umass.edu)
with co-instructors Wil Cruz and Raul Alcantara.
Organized by
Sarah Elgin and April Bednarski
Registration:
http://becker.wustl.edu/news/bioinfo-workshop-form.htm
Supported in part by the Washington University Biology Dept. and
Becker Medical Library and by a grant to Washington University,
St Louis, in support of Sarah C.R. Elgin from the Howard Hughes
Medical Institute through its Professors Program.
- Tuesday 8/24/04:
Hilltop Campus (Natural Science Learning Center, Rm. 117),
8am-4pm (12-1pm lunch break).
-
Wednesday 8/25/04:
Medical Campus (Becker Medical Library, Rm. 601A),
8am-2:30pm (lunch break 11:30am-12:30pm).
-
Thursday 8/26/04:
Hilltop Campus (Natural Science Learning Center, Rm. 117),
8am-4pm (lunch break 12-1pm).
http://www.nslc.wustl.edu/martz/
- Mac downloads: Netscape
and Chime plug-in.
- Windows downloads: Netscape
and Chime plug-in.
This document is on-line: At proteinexplorer.org click on Workshops, or
http://www.umass.edu/molvis/workshop/washu04.htm
or at Washington University
www.nslc.wustl.edu/martz/PEsyllabus.htm
Rationale & Goals: 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 drug design. This workshop will
enable participants to find published macromolecular structure data, and visualize
and interpret 3D macromolecular structure. Participants will be enabled to
incorporate computer visualization and qualitative analysis
of 3D structure of protein, DNA, RNA, and protein-ligand
interactions 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 in a Windows
subsystem), and is much easier to use, yet much
more powerful than RasMol.
Protein Explorer won the
2003 MERLOT Classic Award in Biology
for exemplary online learning resources:
"The Protein Explorer has revolutionized the teaching of
biology at a molecular level".
Protein Explorer integrates several key bioinformatics
servers, and
has been adopted by
numerous
bioinformatics resources.
Level & Pace: This workshop is designed for
researchers familiar with basic biochemistry, but with no
previous molecular visualization software experience.
It progresses rapidly to powerful tools that will be of interest
to 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 to discover within
Protein Explorer and its links to other resources!
Day 1, Tuesday August 24.
Basics.
How to use Protein Explorer to visualize structural features of
proteins and protein-ligand interactions.
|
Netscape 4.8 is best, but Internet Explorer is OK.
Go to www.proteinexplorer.org
Skip the PE Demo Movies -- use them for review (if you haven't used PE for a few months)
or to start friends who didn't attend this course.
FirstView
- Click Quick-Start ... to display Gal4:DNA.
- Organization of PE into 3 frames: control panel, molecular image, and messages.
- Use the mouse to rotate the molecule; click to identify atoms.
- Identify and become familiar with the computer representations for chains, backbones, disulfide bonds, solvent, and ligands.
Features of the Molecule
- Understanding and using information provided in the PDB file header
by the authors of the structure.
- The Help/Index/Glossary (green for "go"), a
major component of PE's knowledge base.
QuickViews
- Selecting, emphasizing, and hiding portions of the molecule.
- Selecting arbitrary atoms/chains/residues by clicking on them.
- Saving/recalling selected sets.
- 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. (Cf. 104d)
- Coloring by disorder: temperature factor coloring.
- PE Site Map
Global
Protein Structure Issues
- How are 3D macromolecular structures obtained?
Crystallography,
NMR, and homology modeling.
- What fraction of the human proteome has known structure?
A few percent.
- Is
Structural
Genomics the answer?
Not
in the next few years.
- Intrinsicially unstructured proteins:
About 10% of proteins are thought to be fully disordered to support
their functions, and 40% of eukaryotic proteins have at least one
long disordered region.
Examples.
- Finding published molecules of interest:
Browsing
- Atlas of MacroMolecules:
molvis.sdsc.edu/atlas/atlas.htm
- PDB at a Glance:
cmm.info.nih.gov/modeling/pdb_at_a_glance.html
Searching
- PDB Lite:
www.pdblite.org
- SearchFields at the Protein Data Bank
www.pdb.org
- Prilusky's OCA
http://bioportal.weizmann.ac.il/oca-bin/ocamain
Sequences
Residue ranges for the CDR's in the Fab of 1FDL are:
Heavy chain (H)
- CDR1: 31-35
- CDR2: 50-66
- CDR3: 98-105
Light chain (L)
- CDR1: 24-34
- CDR2: 50-56
- CDR3: 90-97
For shortcuts and tricks in using PE to visualize epitope-paratope
contacts, see step #35 in this
Antibody Structure Tutorial.
|
- OPTIONAL: Protein Explorer's Sequence display - finding gaps
- 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
(see example in box at right).
- Noncovalent Bonds: Contact surfaces. Example: Gal4 contacting DNA (1d66), showing:
- Sequence specific recognition DNA bases by zinc finger domain of protein
- Hydrophobic protein-protein interaction
- Nonspecific charge interactions at DNA backbone phosphates
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Day 2, Wednesday August 25.
Supplementary Bioinformatics Servers
and
PE at Full Power
|
- External Resources (via PE Site Map)
- Probable Quaternary Structures: specific oligomers: 1k28, 1k93,
virus
capsids.
vs. Crystal Contacts (4mdh).
- ConSurf: regions conserved or hypermutable in evolution
- MolProbity: all-atom contact analysis -- add hydrogens, then
- See and correct Asn, Gln, His side-chain flips
- See atomic clashes and evaluate overall clash score (1cbx)
- Visualizing Cation-Pi interactions and Salt Bridges (QuickViews, DISPLAY; 1b07, 1axi)
- QuickViews Boolean (scroll down in the QuickViews control panel).
- Example: In 1FDL, display Fab atoms contacting lysozyme, then
overlay (
DISPLAY) a cartoon display of all protein. Color the cartoon
by Chain, then by N->C Rainbow, then by Structure.
- Multiple-Model NMR Results (1JSA, 1CFC)
- Most representative model (via PE Site Map -> External Resources).
- NMR Control Panel.
- Animation simulates thermal motion (Click "Animations" at the FrontDoor).
- Animations: Morphing conformational changes (Click "Animations" at the FrontDoor).
- Protein Comparator (via Quick-Start Comparator at the FrontDoor;
(snapshot)
- Preferences in Protein Explorer (beneath the message box).
- Aliases for RasMol/Chime commands (beneath the message box).
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Day 3 - Thursday August 26:
Resources for Educators and Special Projects
|
The Day 3 agenda will be flexible. Individual help will be available
for those with special projects.
MolVis Resources for Educators
- Lesson Plans (at PE's FrontDoor)
- About Protein Structure (at PE's FrontDoor)
- World Index of Molecular Visualization Resources
molvisindex.org
- Hundreds of Chime-based tutorials indexed by macromolecule
- Chime-based resources en Español
- Sources of atomic coordinate (PDB) files (metabolites, inorganic crystals, lipid micelles, etc.)
- Galleries, Molecular Sculpture and Physical Models, Software
- Martz Chime Resources
www.umass.edu/microbio/chime
- Amino Acid Quizzer
- DNA, Hemoglobin, Antibody, MHC
- Lipid Bilayers and Gramicidin Channel
- IR Spectra with animated vibrations
- Toobers in Science Education
- History of Visualization of Biological Macromolecules
Where did Chime come from? What about Fred's Folly and Byron's
Bender? See early computer images, physical models including the latest by
computer-driven laser-powered rapid-prototype engineering, and the latest
molecular sculpture.
- Knots in Proteins
- Building a web page with hyperlinks to Protein Explorer that
prespecify molecules for your teaching or research.
Examples.
Methods.
Detailed methods.
- Presenting molecular structures in Chime websites:
- A well tested and debugged
template for Chime presentations
exists but is nearly obsolete.
- A Chime-based Script recorder within PE
is nearly completed. With it, views achieved in PE can be saved
(as Chime command scripts) and played back.
Although not yet released, a
pre-release working version is available.
- Support for Presentations in Protein Explorer (PiPE)
remains under development and has not been released.
A partial implementation of a new design has a
viewable
example
and is
downloadable. Although it is in rough shape
at this time,
a couple of people have already developed educational resources with it.
An
earlier design is now deemed obsolete and will not be supported.
Additional topics by request, time permitting (or to explore on your own):
- 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).
- DeepView
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, but will need
manual editing to separate models with MODEL [N] and ENDMDL
records so that Protein Explorer can distinguish the models.
Gale Rhodes provides a
DeepView tutorial: click on the section Comparing Proteins.
- Mutating your model:
-
Changing residue sidechains and rotamer minimization with DeepView
- DeepView beginners should start with the superb
Molecular Modeling for Beginners
by Gale Rhodes, Univ. Southern Maine.
- DeepView resources are indexed at
molvisindex.org.
- Searching by structure without reference to sequence:
(Try the bacterial cell division protein 1FSZ§.)
Structure is more conserved than sequence!
(Chothia
et al., 2003;
Precis)
- Shindyalov & Bourne's Combinatorial Extension
cl.sdsc.edu/ce.html
- NCBI's Vector Alignment Search Tool (VAST)
www.ncbi.nlm.nih.gov/Structure/VAST/vast.shtml
- External Resources (via PE Site Map)
- Crystal Contacts
- Fewer or Single Chains
- Model Quality (& examples of errors in published PDB files)
- RCSB's Structure Explorer
- NCBI's Entrez Structure
Advanced Explorer
- The Noncovalent Bond Finder
- Rolling probe surfaces and molecular electrostatic potential coloring
- Including ligands in displays of cation-pi interactions and salt bridges
- Morphing conformational changes to view as
animations in PE: see
Protein Morpher.
- Homology (comparative) modeling:
Introduction.
Keep in touch!
- Molecular Visualization Freeware/Education email list,
PDB email discussion, etc. available from
molvisindex.org.
- Yours truly:
emartz@microbio.umass.edu (But please direct questions about RasMol
or Chime or Protein Explorer to the RasMol list, first item above.)
- Collaborations are invited that use
Protein Explorer to display information about macromolecular structure,
particularly information which may be the result of your research.
The only example
to date
involving customization of PE is
ConSurf. PE is used without modification by several other
bioinformatics servers.
§ Example 1FSZ thanks to Gabe McCool. See also his
presentation on 1FSZ in PE.