After the sequence alignment section you will not yet be able to align sequences yourself, but you will understand why sequence alignment is needed and how they can be used in the protein structure bioinformatics arena. |
During evolution many small and the occasional big thing happen to DNA. Some of these DNA modification will lead also to protein modifications. Most protein modifications likely are harmful for the species so that the branch of the species with this modification will die out quickly. But sometimes the mutation is neutral to the species or even beneficial, and then the mutation survives over time.
After many years this evolutionary process has progressed so far that we have obtained different species as straight descendants from one species; divergent evolution.
We use sequence alignments to find out if sequences are (likely) homologous, and which amino acids descended from the same ancesteral amino acid. This is important when we want to do homology modelling.
Multiple sequence alignments can also tell us which residues are conserved, and thus important, and thus should not be mutated when doing protein engineering experiments.
All-and-all multiple sequence alignments are probably the most important tool in bioinformatics, even when studying protein structures.