ISSN:
1432-1432
Keywords:
Statistical Analysis
;
Amino Acid Composition
;
Evolution of Subunits in Ribulose Diphosphate Carboxylase
Source:
Springer Online Journal Archives 1860-2000
Topics:
Biology
Notes:
Abstract Aϰ 2 analysis was made of previously reported values for the amino acid composition of the large and small subunits of ribulose diphosphate carboxylase (E.C. 4, 1, 1, 39) isolated from five species ofNicotiana. The distributions of these values were then compared with published values for hemoglobinα chains and cytochromec's of diverse origins. It was concluded that evolutionary diversity in the large and small subunits of RuDP carboxylase occurs even within the limited taxonomic category of the genusNicotiana. The large subunit was as stable towards mutation during evolution as theα chains and cytochromes, whereas the small subunit was much less stable. The hypothesis is discussed that the large subunit played a more significant role than the small subunit in the enzyme function and/or structural integrity of the oligomeric protein. It was also speculated that the addition of small subunits to the molecule, which may have been a recent evolutionary event, enables the fixation of many evolutionarily favorable mutations. Thus, survival of the enzymatic activity in changing environments is favored.
Type of Medium:
Electronic Resource
URL:
http://dx.doi.org/10.1007/BF01796555
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