Globin evolution

Arthur Lesk and Cyrus Chothia at the MRC Laboratory of Molecular Biology in Cambridge, UK, compared the family of globin strucfures with the aim of answering two general questions How can amino acid sequences that are very different form proteins that are very similar in their three-dimensional structure What is the mechanism by which proteins adapt to mutations in the course of their evolution ... 

Blaxter, M.L., Ingram, L. and Tweedie, S. (1994a) Sequence, expression and evolution of the globins of the nematode Nippostrongylus brasiliensis. Molecular and Biochemical Parasitology 68, 1-14. 

Many examples of recurring domain or motif structures are available, and these reveal that protein tertiary structure is more reliably conserved than primary sequence. The comparison of protein structures can thus provide much information about evolution. Proteins with significant primary sequence similarity, and/or with demonstrably similar structure and function, are said to be in the same protein family. A strong evolutionary relationship is usually evident within a protein family. For example, the globin family has many different proteins with both structural and sequence similarity to myoglobin (as seen in the proteins used as examples in Box 4-4 and again in the next chapter). Two or more families with little primary sequence similarity sometimes make use of the same major structural... 

Wagner, A., Deryckere, F McMorrow, T and Gannon, F. (1994) Tail-to-Tail Orientation of the Atlantic Salmon Alpha-and Beta-Globin Genes, Journal of Molecular Evolution, 38,28-35. 

Before the evolution of protein function can be studied, functional differences first must be demonstrated between members of the family. At present, the best comparative biochemical data exist for classically studied protein families, such as the globin family and several families of digestive enzymes.3... 

A possible scheme for the evolution of a multigene family The evolution of gene clusters exemplified by the globin genes. 

See also Hemoglobin Variants, Globin Gene Expression in Development, Evolution of Myoglobin/ Hemoglobin Proteins, Mechanisms of Protein Mutation, Hemoglobin... 

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