Structure of glycerol dehydratase reactivase: a new type of molecular chaperone.
The function of glycerol dehydratase (GDH) reactivase is to remove damaged coenzyme B(12) from GDH that has suffered mechanism-based inactivation. The structure of GDH reactivase from Klebsiella pneumoniae was determined at 2.4 A resolution by the single isomorphous replacement with anomalous signal (SIR/AS) method. Each tetramer contains two elongated 63 kDa alpha subunits and two globular 14 kDa beta subunits. The alpha subunit contains structural features resembling both GroEL and Hsp70 groups of chaperones, and it appears chaperone like in its interactions with ATP. The fold of the beta subunit resembles that of the beta subunit of glycerol dehydratase, except that it lacks some coenzyme B(12) binding elements. A hypothesis for the reactivation mechanism of reactivase is proposed based on these structural features.
Liao
Der Ing
DI
DuPont Central Research and Development, Experimental Station, Wilmington, DE 19880, USA. der-ing@usa.dupont.com
Reiss
Lisa
L
Turner
Ivan
I
Dotson
Garry
G
D000251:Adenosine Triphosphatases / Q000737:chemistry; D001426:Bacterial Proteins / Q000737:chemistry*; D018834:Chaperonin 60 / Q000737:chemistry; D018360:Crystallography, X-Ray; D018840:HSP70 Heat-Shock Proteins / Q000737:chemistry; D006836:Hydro-Lyases / Q000737:chemistry*; D007711:Klebsiella pneumoniae / Q000201:enzymology*; D008958:Models, Molecular; D018832:Molecular Chaperones / Q000737:chemistry*; D020836:Protein Structure, Quaternary; D017433:Protein Structure, Secondary; D017434:Protein Structure, Tertiary
D001426:Bacterial Proteins; D018834:Chaperonin 60; D018840:HSP70 Heat-Shock Proteins; D018832:Molecular Chaperones; D000251:Adenosine Triphosphatases; D006836:Hydro-Lyases; C120061:glycerol dehydratase reactivating factor, Klebsiella pneumoniae