Of the vulnerability of orphan complex proteins: the case study of the E. coli IscU and IscS proteins.
Protein Expr Purif
; 73(2): 161-6, 2010 Oct.
Article
em En
| MEDLINE
| ID: mdl-20471481
ABSTRACT
IscS and IscU, the two central protein components of the iron sulfur cluster assembly machinery, form a complex that is still relatively poorly characterized. In an attempt to standardize the purification of these proteins for structural studies we have developed a protocol to produce them individually in high concentration and purity. We show that IscS is a rather robust protein as long as it is produced in a PLP loaded form and that this co-factor is essential for fold stability and enzyme activity. In contrast to previous evidence, we also propose that, in contrast with previous evidence, IscU is a thermodynamically stable protein with a well defined fold but, when produced in isolation, is a 'complex-orphan protein' that is prone to unfolding if not stabilised by a co-factor or a protein partner. Our work will facilitate further structural and functional studies of these proteins and eventually lead to a better understanding of the whole machinery.
Texto completo:
1
Base de dados:
MEDLINE
Assunto principal:
Liases de Carbono-Enxofre
/
Compostos de Sulfonilureia
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Proteínas de Bactérias
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Proteínas
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Proteínas de Escherichia coli
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Proteínas Ferro-Enxofre
Idioma:
En
Revista:
Protein Expr Purif
Assunto da revista:
BIOLOGIA MOLECULAR
Ano de publicação:
2010
Tipo de documento:
Article
País de afiliação:
Reino Unido