Ring Separation Highlights the Protein-Folding Mechanism Used by the Phage EL-Encoded Chaperonin
- Univ. of Texas, El Paso, TX (United States). Department of Chemistry
- Indiana Univ., Bloomington, IN (United States). Department of Chemistry
- University of Texas Medical Branch, Galveston, TX (United States). Department of Biochemistry and Molecular Biology
- Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States). Neutron Scattering Science Division
- Univ. of Utah, Salt Lake City, UT (United States). Department of Biochemistry
- Russian Academy of Sciences, Moscow (Russia). Kharkevich Institute for Information Transmission Problems
- Shemyakin-Ovchinnikov Institute of Bioorganic Chemistry RAS, Moscow (Russia)
Chaperonins are ubiquitous, ATP-dependent protein-folding molecular machines that are essential for all forms of life. Bacteriophage φEL encodes its own chaperonin to presumably fold exceedingly large viral proteins via profoundly different nucleotide-binding conformations. Our structural investigations indicate that ATP likely binds to both rings simultaneously and that a misfolded substrate acts as the trigger for ATP hydrolysis. More importantly, the φEL complex dissociates into two single rings resulting from an evolutionarily altered residue in the highly conserved ATP-binding pocket. Conformational changes also more than double the volume of the single-ring internal chamber such that larger viral proteins are accommodated. This is illustrated by the fact that φEL is capable of folding β-galactosidase, a 116-kDa protein. Collectively, the architecture and protein-folding mechanism of the φEL chaperonin are significantly different from those observed in group I and II chaperonins.
- Research Organization:
- Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States)
- Sponsoring Organization:
- USDOE Office of Science (SC), Biological and Environmental Research (BER); USDOE Office of Science (SC), Basic Energy Sciences (BES)
- DOE Contract Number:
- AC05-00OR22725
- OSTI ID:
- 1352746
- Journal Information:
- Structure, Vol. 24, Issue 4; ISSN 0969-2126
- Publisher:
- Elsevier
- Country of Publication:
- United States
- Language:
- English
Similar Records
Chaperonin polymers in archaea: The cytoskeleton of prokaryotes?
Chaperonin filaments : their formation and an evaluation of methods for studying them.