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The literature and ClustalW2 data support the existence of calmodulin in a variety of eukaryotic species along with the high primary amino acid sequence conservation. This data suggests that the calmodulin protein sequence is important for the function of calmodulin because over time evolution and natural selection has maintained a consistent sequence. In fact, literature has supported such claims referencing the importance of repeated primary sequence domains for each of the 4 calcium binding EF-hands (Nojima, 1987). This data also suggests that calmodulin itself, as a calcium binding signal transducer, is important in various lifeforms and various pathways. Literature also supports these claims by asserting the importance of calcium as a secondary messanger in a multitute of biological pathways that are present in all eukaryotes and asserting the need for calmodulin to transduce such calcium signals (Yang, 2001). We have also learned that the calmodulin protein found in eukaryotes may have evolved from the calmodulin-like calcium binding proteins within prokaryotes (such as E. coli) (Yang, 2001), although concrete evidence does not exist for such claims, they are simply hypothesis. We have also learned that it is possible that throughout evolution some small changes have occurred in the calmodulin sequence in order to establish specific antibody recognition sites (epitopes) across various species (Onek et al., 1992). In conclusion in studying the orthologs of calmodulin, we have discovered more information about the function, importance, and evolutionary past of calmodulin.
Dutta et al. RCSB: Molecule of the Month- Calmodulin [Online]. Avail from: http://www.rcsb.org/pdb/static.do?p=education_discussion/molecule_of_the_month/pdb44_1.html [August 2003].
Klee et al. Calmodulin. Advances in Protein Chemistry 1982; 35: 213-321. Avail from: http://books.google.com/books?id=10rqsL_pR0QC&pg=PA213&lpg=PA213&dq=Advances+in+protein+chemistry.:+CALMODULIN&source=bl&ots=wPtskiBkzk&sig=17qrnjLRvlGk8epHVA8NQ0LZiNQ&hl=en&ei=2ceWS-iME8iUtgeJjejrDQ&sa=X&oi=book_result&ct=result&resnum=1&ved=0CA8Q6AEwAA#.
Lagace et al. Identification of Multiple Species of Calmodulin Messanger RNA Using a Full Length Complementary DNA. The Journal of Biological Chemistry 1982; 258.3: 1684-1688.
Nojima, Hiroshi. Molecular evolution of the calmodulin gene. FEBS Lett 1987; 217.2: 187-190.
Onek et al. Calmodulin and calcium mediated regulation in prokaryotes. Journal of General Microbiology 1992; 138: 1039-1049. Avail from: http://mic.sgmjournals.org/cgi/reprint/138/6/1039.
Stevens, F. C. Calmodulin: an introduction. Canadian Journal of Biochemistry and Cell Biology 1983; 61: 906-910.
Yang, Keqian. Prokaryotic Calmodulin Recent Developmentsand Evolutionary Implications. J Mol Microbiol Biotechnol 2001; 3: 457-459. Avail from: http://www.horizonpress.com/jmmb/v3/v3n3/16.pdf.
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