This page was created for University of Wisconsin undergraduate course Genetics 564
What is Protein Homology?
Protein homology analyzes the ancestral connections between different species by comparing similar protein sequences found within their cells. The more conserved, or the same, a protein sequence is, the closer relatives the two species likely are. Knowing which species have homologs, or very similar protein sequences, to humans is important because it allows the study of the protein in other animals without having to resort to unethical and costly human studies. We can use homologous proteins in other species to learn more about the protein's function in humans.
EFHC1 Protein Homology
Many homologs of the EFHC1 protein exist in other species. These homologous proteins were found using BLAST, an alignment search tool that uses the amino acid sequence of human EFHC1 protein and finds matches in other species. Homologs were also verified using Homologene, a database of protein sequences that lists verified homologs from previous scientific research.
Analysis:
BLAST search results revealed many homologous proteins displayed in Image 1 above, ranked by similarity. The most similar protein is the EFHC1 protein in chimpanzee, having a sequence identity of 99%. The other mammals also had high sequence similarities. EFHC1 is also found in zebra fish and mosquito, two more distant relatives of humans. An EFHC1 protein homolog is also found in green algae, single cellular organisms found in aquatic environments. This homolog was surprising given that green algae lack any nervous system and thus have no ties to epilepsy. This indicates EFHC1's importance in processes beyond just neuronal firing.
BLAST search results revealed many homologous proteins displayed in Image 1 above, ranked by similarity. The most similar protein is the EFHC1 protein in chimpanzee, having a sequence identity of 99%. The other mammals also had high sequence similarities. EFHC1 is also found in zebra fish and mosquito, two more distant relatives of humans. An EFHC1 protein homolog is also found in green algae, single cellular organisms found in aquatic environments. This homolog was surprising given that green algae lack any nervous system and thus have no ties to epilepsy. This indicates EFHC1's importance in processes beyond just neuronal firing.
Human - (homo sapien) - EFHC1 protein
Percent Identity: 100% FASTA Accession: NP_060570 Chimpanzee - (pan troglodytes) - EFHC1 protein Percent Identity: 99% FASTA Accession: NP_001267272 E-value: 0.0 Horse - (equus caballus ) - EFHC1 protein Percent Identity: 91% FASTA Accession: XP_001499017 E-value: 0.0 Chicken - (gallus gallus) - EFHC1 protein Percent Identity: 67% FASTA Accession: XP_420047 E-value: 0.0 |
Mouse - (mus musculus) - EFHC1 protein
Percent Identity: 84% FASTA Accession: NP_082250 E-value: 0.0 Zebrafish - (danio rerio) - EFHC1 protein Percent Identity: 53% FASTA Accession: NP_957261 E-value: 0.0 Mosquito - (anopheles gambiae ) - AGAP003805 protein Percent Identity: 42% FASTA Accession: XP_310360 E-value: 8x10^-144 Green Algae - (Chlamydomonas) - Rib72 protein Percent Identify: 40% FASTA Accession: EDP06952 E-value: 0.0 |
References:
Image 1: http://asia.genesilico.pl/colorado3d/
Image 1: http://asia.genesilico.pl/colorado3d/