A combination of structural and cis-regulatory factors drives biochemical differences in Drosophila melanogaster malic enzyme.
Biochem Genet
; 50(11-12): 823-37, 2012 Dec.
Article
em En
| MEDLINE
| ID: mdl-22733181
ABSTRACT
The evolutionary significance of molecular variation is still contentious, with much current interest focusing on the relative contribution of structural changes in proteins versus regulatory variation in gene expression. We present a population genetic and biochemical study of molecular variation at the malic enzyme locus (Men) in Drosophila melanogaster. Two amino acid polymorphisms appear to affect substrate-binding kinetics, while only one appears to affect thermal stability. Interestingly, we find that enzyme activity differences previously assigned to one of the polymorphisms may, instead, be a function of linked regulatory differences. These results suggest that both regulatory and structural changes contribute to differences in protein function. Our examination of the Men coding sequences reveals no evidence for selection acting on the polymorphisms, but earlier work on this enzyme indicates that the biochemical variation observed has physiological repercussions and therefore could potentially be under natural selection.
Texto completo:
1
Coleções:
01-internacional
Base de dados:
MEDLINE
Assunto principal:
Polimorfismo Genético
/
Sequências Reguladoras de Ácido Nucleico
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Proteínas de Insetos
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Drosophila melanogaster
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Malato Desidrogenase
Limite:
Animals
Idioma:
En
Revista:
Biochem Genet
Ano de publicação:
2012
Tipo de documento:
Article
País de afiliação:
Canadá