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Printable Handouts
Navigable Slide Index
- Introduction
- The concept of information
- Three related concepts
- What the three concepts have in common
- Example
- Brand A
- Brand B
- Comparative variety
- Diversity, variety, uncertainty, choice
- Application to protein sequences
- Multiple sequence alignment
- Hb family - multiple sequence alignment
- 2nd Example
- Portion of Hb MSA, positions 13, 18, and 21
- Amino acid counts
- Brand "Hb MSA position 13"
- Brand "Hb MSA position 18"
- Brand "Hb MSA position 21"
- Comparative variety
- Calculating "effective number"
- Counting kinds - entropy
- Counting kinds - uncertainty
- Entropy - definition
- Purpose
- Sequence variation in Hb
- Variability of sequences from selected families
- The nature of variation
- Three examples of nonsense
- Comparison to English sentences
- Lower entropy
- What kinds of patters reduce entropy?
- Conservative substitutions
- Amino acid substitution matrices
- Blosum62 matrix
- Extracting similarity
- Amino acid similarity circle
- Information
- Characteristics of information
- How is information measured?
- Measuring information from a "stand in"
- Two correlated collections
- Example: codon middle base and hydrophobicity
- Genetic code vs. amino acid hydrophobicity
- Codon properties
- Codon properties - comparison
- Collection 1 - codon middle base
- Brand codon - middle-base
- Collection 2 - amino acid solubility
- Brand amino acid - water solubility
- Correlation between R-Y and hydrophobicity
- Matches/mismatches between properties
- Brand correlated
- What distribution results from random association
- Brand no-correlation
- Technical definition of information
- Brands correlated vs. uncorrelated
- Hydrophobicity information provided by middle base
- Meaning of entropy and information - summary
- Application - blast
- Blast - bit score
- Application - correlated substitutions
- Multiple sequence alignment
- Old concept: strict constraints
- New concept: few constraints
- Hypothetical multiple sequence alignment
- Zooming in, MSA
- Zooming in equilibrium site
- Conserved site
- Correlations
- Results
- Experimental tests
- Proteins are very tolerant of mutations
- A minority of amino acid sites dictates structure
- Sequence similarity
- Protein sequences have patterns
- Sequence and structure
- Structure is more preserved than sequence
- 1RHD sequence alignment
- 1RHD sub-sequence alignment
- Chain path of entire molecule
- Beta-alpha-beta motifs in 1RHD (1)
- Two fold symmetry axis
- Beta-alpha-beta motifs in 1RHD (2)
- Beta-alpha-beta motifs in 1RHD (3)
- How much does a family of proteins vary?
- How much do similar protein structures differ?
- 3-d match closeness
- Representation of degree of agreement
- Structure prediction
- Sequence determines structure
- Structures are more conserved than sequences
- One structure for a sequence family is enough
- How is a structure predicted?
- Gallery of faces
- Components of faces
- Artist's renditions
- Second structure prediction
- Gallery of proteins
- Components of proteins
- Unknown structure
- Fragments of extended chain
- Placement
- Folded chain creation
- Touch up
- Successful de novo prediction characteristics
- The line up
- Example: experiment vs. prediction (1)
- Example: experiment vs. prediction (2)
- Example: experiment vs. prediction (3)
- Example: experiment vs. predictionX
- Example: experiment, prediction and predictionX
- Context
- Aggregated vs. globular
- Sequence and context determine structure
- References
- References: Mr. Peanut
- References: monkeys typing
- References: genetic code
- References: ranganathan
- References: police artist
- References: Casp
- References: Velcro
Topics Covered
- Concept of information
- Variation in protein sequences
- Patterns
- Comparison with language
- Measuring information
- Genetic code
- Correlated substitutions
- Proteins' high tolerance for substitutions
- Protein structure prediction
- Dependence of structure on environment
Talk Citation
Swanson, R. (2017, October 31). Information content in sequences and its relation to protein structure prediction [Video file]. In The Biomedical & Life Sciences Collection, Henry Stewart Talks. Retrieved April 15, 2025, from https://doi.org/10.69645/SKRI2193.Export Citation (RIS)
Publication History
Financial Disclosures
- Dr. Rosemarie Swanson has not informed HSTalks of any commercial/financial relationship that it is appropriate to disclose.
Information content in sequences and its relation to protein structure prediction
A selection of talks on Biochemistry
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