08 - modintro

08 modintro - The creation of a three dimensional structural image of a protein using its amino acid sequence and the principles and our knowledge

Info iconThis preview shows pages 1–3. Sign up to view the full content.

View Full Document Right Arrow Icon
Protein Structure Modelling –What is it? The creation of a three dimensional structural image of a protein, using its amino acid sequence and the principles, and our knowledge, of protein structure. An application of theory, not experiment, resulting in a theoretical model. Why do this? Structure allows protein molecules to function. We will see that sequence, structure and function are interrelated in ways that allow us to connect each to the others. Building models of proteins allows us to understand function and plan experiments more effectively. Why Model? Just Solve All the Structures! X-ray methods need proteins that form crystals. NMR methods need proteins that are soluble (at millimolar concentrations). Both take months to years per protein. A model based on a known structure can be made quickly. Models can be used to test mutations or rebuilt and refined if new information becomes available. Some Genomic Thoughts The Yeast Genome has 6,000 (protein coding) genes. The Human Genome has 20-25,000 (40,000?) genes. A large proportion of genes found in new genomes cannot be assigned a function. Exploring sequence-structure compatibility will help assign functions. There are 1000 times as many sequences as structures and the gap is widening. Theoretical means, such as modelling, are the only way we can manage the task of inferring function (and so directing experiments) for new genomes. Database Growth Log scale – exponential growth! There are 48,638 structures but 80,388,382 nucleic acid sequences ( 83,874,179,730 nucleotides ). A vast sequence/structure mismatch. New sequences are found faster than we can solve structures. The apparently small number of folds helps us to predict structures for sequences. Comparison methods are of great importance.
Background image of page 1

Info iconThis preview has intentionally blurred sections. Sign up to view the full version.

View Full DocumentRight Arrow Icon
Should You Model? Some Crystallographers say No! Modelling is - not experimental! - a guess! - wrong! - to some degree - how much? / how little? Many “Gels and Cells” People Think Not! But! How do you: • explain your mutations?
Background image of page 2
Image of page 3
This is the end of the preview. Sign up to access the rest of the document.

This note was uploaded on 07/29/2010 for the course BIOC BIOC2811 taught by Professor Dr.q.hao during the Summer '10 term at HKU.

Page1 / 6

08 modintro - The creation of a three dimensional structural image of a protein using its amino acid sequence and the principles and our knowledge

This preview shows document pages 1 - 3. Sign up to view the full document.

View Full Document Right Arrow Icon
Ask a homework question - tutors are online