The Extended C-Terminal α-Helix of the HypC Chaperone Restricts Recognition of Large Subunit Precursors by the Hyp-Scaffold Machinery during [NiFe]-Hydrogenase Maturation in Escherichia coli.
J Mol Microbiol Biotechnol
; 28(2): 87-97, 2018.
Article
en En
| MEDLINE
| ID: mdl-29996137
ABSTRACT
Members of the HypC protein family are chaperone-like proteins that play a central role in the maturation of [NiFe]-hydrogenases (Hyd). Escherichia coli has a second copy of HypC, called HybG, and, as a component of the HypDEF maturation scaffold, these proteins help synthesize the NiFe-cofactor and guide the scaffold to its designated hydrogenase large subunit precursor. HypC is required to synthesize active Hyd-1 and Hyd-3, while HybG facilitates Hyd-2 and Hyd-1 synthesis. To identify determinants on HypC that allow it to discriminate against Hyd-2, we made amino acid exchanges in 3 variable regions, termed VR1, VR2, and VR3, of HypC, that make it more similar to HybG. Region VR3 includes a HypC-specific C-terminal α-helical extension, and this proved particularly important in preventing the maturation of Hyd-2 by HypC. Truncation of this extension on HypC increased Hyd-2 activity in the absence of HybG, while retaining maturation of Hyd-3 and Hyd-1. Combining this truncation with amino acid exchanges in VR1 and VR2 of HypC negatively affected the synthesis of active Hyd-1. The C-terminus of E. coli HypC is thus a key determinant in hindering Hyd-2 maturation, while VR1 and VR2 appear more important for Hyd-1 matu-ration.
Palabras clave
Texto completo:
1
Colección:
01-internacional
Banco de datos:
MEDLINE
Asunto principal:
Chaperonas Moleculares
/
Proteínas de Escherichia coli
/
Escherichia coli
/
Conformación Proteica en Hélice alfa
/
Hidrogenasas
Tipo de estudio:
Prognostic_studies
Idioma:
En
Revista:
J Mol Microbiol Biotechnol
Asunto de la revista:
BIOLOGIA MOLECULAR
/
BIOTECNOLOGIA
/
MICROBIOLOGIA
Año:
2018
Tipo del documento:
Article