>The following paper is very important in connection with protein evolvability: Douglas D. Axe...J.Mol.Biol. 301 (2000), 585-95.
>Axe's abstract: "... This is found to cause complete loss of function in vivo ..."
>
>This shows that previous estimates of the number of different possible sequences that might show a given biological activity, such as H.P. Yockey's ("Information theory and molecular biology" (Cambridge: Cambridge Univ.Press, 1992), p.254), are likely to be vast overestimates because they neglect possible interdependencies between different amino-acid positions...
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Not necessarily. Axe looked at the function of the modified proteins in vivo. Such large numbers of changes are unlikely to happen all at once in real organisms, so that coevolution of associated proteins is possible. As an example, mitochondrial rDNA genes do not even use the same genetic code as nuclear rDNA genes, so they cannot be interchanged, yet both successfully perform the same function
Dr. David Campbell
"Old Seashells"
Biology Department
Saint Mary's College of Maryland
18952 E. Fisher Road
St. Mary's City, MD 20686-3001 USA
dcampbell@osprey.smcm.edu, 301 862-0372 Fax: 301 862-0996
"Mollusks murmured 'Morning!'. And salmon chanted 'Evening!'."-Frank Muir, Oh My Word!
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