Asp-52 in combination with Asp-398 plays a critical role in ATP hydrolysis of chaperonin GroEL.
J Biol Chem
; 289(43): 30005-11, 2014 Oct 24.
Article
em En
| MEDLINE
| ID: mdl-25202010
ABSTRACT
The Escherichia coli chaperonin GroEL is a double-ring chaperone that assists protein folding with the aid of GroES and ATP. Asp-398 in GroEL is known as one of the critical residues on ATP hydrolysis because GroEL(D398A) mutant is deficient in ATP hydrolysis (<2% of the wild type) but not in ATP binding. In the archaeal Group II chaperonin, another aspartate residue, Asp-52 in the corresponding E. coli GroEL, in addition to Asp-398 is also important for ATP hydrolysis. We investigated the role of Asp-52 in GroEL and found that ATPase activity of GroEL(D52A) and GroEL(D52A/D398A) mutants was â¼ 20% and <0.01% of wild-type GroEL, respectively, indicating that Asp-52 in E. coli GroEL is also involved in the ATP hydrolysis. GroEL(D52A/D398A) formed a symmetric football-shaped GroEL-GroES complex in the presence of ATP, again confirming the importance of the symmetric complex during the GroEL ATPase cycle. Notably, the symmetric complex of GroEL(D52A/D398A) was extremely stable, with a half-time of â¼ 150 h (â¼ 6 days), providing a good model to characterize the football-shaped complex.
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Base de dados:
MEDLINE
Assunto principal:
Trifosfato de Adenosina
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Ácido Aspártico
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Chaperonina 60
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Escherichia coli
Idioma:
En
Ano de publicação:
2014
Tipo de documento:
Article