Mammalian Tropoelastin: Multiple Domains of the Protein Define an Evolutionarily Divergent Amino Acid Sequence

• Published in: Matrix (Stuttgart) Vol. 11; no. 4; pp. 235 - 241
• Main Authors: Boyd, Charles D., Christiano, Angela M., Pierce, Richard A., Stolle, Catherine A., Deak, Susan B.
• Format: Journal Article
• Language: English
• Published: Stuttgart Fischer 01.08.1991
• Subjects: Amino Acid Sequence; Analytical, structural and metabolic biochemistry; Animals; Biological and medical sciences; Cattle; Chromosome Deletion; DNA Transposable Elements; evolutionary divergence; Fundamental and applied biological sciences. Psychology; Glycoproteins; Humans; mammalian tropoelastin; Protein Conformation; Proteins; Rats; Time Factors; Tropoelastin - chemistry; Tropoelastin - genetics; mammalian tropoelastin; evolutionary divergence; Human; Bovine; Rat; Interspecific comparison; Rodentia; Glycoproteins; Tropoelastin; Molecular evolution; Vertebrata; Mammalia; Artiodactyla; Ungulata; Comparative study; Aminoacid sequence
• ISSN: 0934-8832
• DOI: 10.1016/S0934-8832(11)80230-1

We have recently derived the complete amino acid sequence of rat tropoelastin from a series of overlapping cDNA clones. Comparison of this protein sequence to bovine and human tropoelastin has revealed significant differences in the rates of evolutionary divergence of the various domains of tropoelastin. The overall rate of divergence of the hydrophobic domains of tropoelastin was twice as fast as the cross-link domains of the protein. Certain hydrophobic domains, however, are as conserved as cross-link regions, particularly the hydrophobic sequence coded for by exon 33, the only exon subject to alternate usage in all three mammalian species and the most conserved domain in rat, bovine and human tropoelastin. This conservation of sequence strongly suggests a more complex function for the hydrophobic region encoded by exon 33, beyond the elastic recoil characteristic of all hydrophobic domains of tropoelastin. A comparison of average rates of divergence of hydrophobic and cross-link domains of tropoelastin to functionallydefined domains of other structural proteins, such as collagen, has also revealed that overall, tropoelastin is a highly divergent amino acid sequence, comparable to proteins such as globin and the fibrino-peptides.