What is homology modelling?
Homology modelling, also known as comparative modelling, is a computational technique used in bioinformatics to predict the three-dimensional structure of a protein when its structure is unknown, but similar proteins (known as homologs) with known structures exist. This method is based on the principle that proteins with similar amino acid sequences tend to fold into similar structures.
The process of homology modelling involves several steps:
- Identification of Homologous Proteins: First, the amino acid sequence of the unknown protein is compared to a database of proteins with known structures to find similar sequences.
- Alignment of Sequences: The next step is aligning the sequence of the unknown protein with that of the known protein(s). This involves matching the amino acids of the two proteins as closely as possible.
- Model Building: Based on this alignment, a model of the unknown protein’s structure is built.
- Refinement and Validation: The model is then refined to make it more accurate and tested to see if it makes sense biologically.
For example, let’s say scientists know the structure of a protein from humans and want to predict the structure of a similar protein in fish. They would use the human protein as a template to model the fish protein, assuming that because the sequences are similar, their structures will be too.
Homology modelling is a powerful tool in drug design and understanding protein function. It helps scientists study proteins that are difficult to analyse experimentally, offering insights into how proteins work and interact with other molecules, which is crucial in fields like medicine and biotechnology.
