Evolutionary divergence

Lesk and Chothia did find, however, that there is a striking preferential conservation of the hydrophobic character of the amino acids at the 59 buried positions, but that no such conservation occurs at positions exposed on the surface of the molecule. With a few exceptions on the surface, hydrophobic residues have replaced hydrophilic ones and vice versa. However, the case of sickle-cell hemoglobin, which is described below, shows that a charge balance must be preserved to avoid hydrophobic patches on the surface. In summary, the evolutionary divergence of these nine globins has been constrained primarily by an almost absolute conservation of the hydro-phobicity of the residues buried in the helix-to-helix and helix-to-heme contacts. 

The globin fold has been used to study evolutionary constraints for maintaining structure and function. Evolutionary divergence is primarily constrained by conservation of the hydrophobicity of buried residues. In contrast, neither conserved sequence nor size-compensatory mutations in the hydrophobic core are important. Proteins adapt to mutations in buried residues by small changes of overall structure that in the globins involve movements of entire helices relative to each other. 

Mackenzie PI, Owens IS, Burchell B, Bock KW, Bairoch A, Belanger A et al. The UDP glycosyltransferase gene superfamily recommended nomenclature update based on evolutionary divergence. Pharmacogenetics 1997 7[4] 255-269. 

Zuckerkandl, E., and Pauling, L. (1965). Evolutionary divergence and convergence in proteins. In Evolving Genes and Proteins (V. Bryson and H. J. Vogel, eds.), pp. 97-166. Academic Press, New York. 

Dias AP, Braun EL, McMullen MD, Grotewold E. 2003. Recently duplicated maize R2R3 Myb genes provide evidence for distinct mechanisms of evolutionary divergence after duplication. Plant Physiol 131 610-620. 

DeSimone DW, Hynes RO. Xenopus laevie integrins. Structural conservation and evolutionary divergence of integrin beta. J Biol Chem 1988 263(1 l) 5333 5340. 

The evolutionary divergences are strictly bifurcating, so that the observed data can be represented by a treelike phylogeny. 

Tyagi N, Swapna LS, Mohanty S et al (2009) Evolutionary divergence of Plasmodium falciparum sequences, protein-protein interactions, pathways and processes. Infect Disord Drug Targets 9 257-271... 

Makarova KS, Grishin NV (1999) The Zn-peptidase superfamily functional convergence after evolutionary divergence. J Mol Biol 292 11-17... 

Talevich E, Mirza A, Kannan N (2011) Structural and evolutionary divergence of eukaryotic protein kinases in Apicomplexa. BMCEvol Biol 11 321... 

Perona, J. J., and Craik, C. S. (1997). Evolutionary divergence of substrate specificity within the chymotrypsin-like serine protease fold. J. Biol. Chem., 272, 29987-29990. 

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