Bioinformatics to study proteins

Evolution A proteins perspective.

From bacteria to humans there are 4 different dNTPs( precursor for DNA) 4 NTPs (precursor to RNA) and 20 different amino acids( precursor to proteins) . Potential for identical sequences to exist between species. A similar sequence means similar structure which means similar function.

Homology

Similar structure+ similar function. Molecules are homologous if they have been derived from a common ancestor.

Orthologs

present within different species and have very similar or identical functions

Paralogs

Present in same species but hav edifferent functions.

structures and sequences

The primary sequence of proteins can also be used to asses homologous relationships. Structure info is minimal. sequence information is more readily available.

Protein sequence comparison

Sequence similarity between 2 proteins implies they likely have same evolutionary origin use sequence alignments to figure it out

Gaps in sequences

Proteins split in evolution so they may have added or deleted amino acids. some machines insert those gaps and can be between conserved amino acids.

Conserved

A sequence structure or biochemical feature has remained unchanged mostly through evolution.