Dataset Information

Ring Separation Highlights the Protein-Folding Mechanism Used by the Phage EL-Encoded Chaperonin.

ABSTRACT: Chaperonins are ubiquitous, ATP-dependent protein-folding molecular machines that are essential for all forms of life. Bacteriophage ?EL 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 ?EL 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 ?EL is capable of folding ?-galactosidase, a 116-kDa protein. Collectively, the architecture and protein-folding mechanism of the ?EL chaperonin are significantly different from those observed in group I and II chaperonins.

SUBMITTER: Molugu SK

PROVIDER: S-EPMC4823152 | biostudies-literature | 2016 Apr

REPOSITORIES: biostudies-literature

ACCESS DATA

Publications

Ring Separation Highlights the Protein-Folding Mechanism Used by the Phage EL-Encoded Chaperonin.

Molugu Sudheer K SK Hildenbrand Zacariah L ZL Morgan David Gene DG Sherman Michael B MB He Lilin L Georgopoulos Costa C Sernova Natalia V NV Kurochkina Lidia P LP Mesyanzhinov Vadim V VV Miroshnikov Konstantin A KA Bernal Ricardo A RA

Structure (London, England : 1993) 20160317 4

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 ri ...[more]

PMID: 26996960

Similar Datasets

Project description:Group I chaperonins are large cylindrical-shaped nano-machines that function as a central hub in the protein quality control system in the bacterial cytosol, mitochondria and chloroplasts. In chloroplasts, proteins newly synthesized by chloroplast ribosomes, unfolded by diverse stresses, or translocated from the cytosol run the risk of aberrant folding and aggregation. The chloroplast chaperonin system assists these proteins in folding into their native states. A widely known protein folded by chloroplast chaperonin is the large subunit of ribulose 1,5-bisphosphate carboxylase/oxygenase (Rubisco), an enzyme responsible for the fixation of inorganic CO2 into organic carbohydrates during photosynthesis. Chloroplast chaperonin was initially identified as a Rubisco-binding protein. All photosynthetic eucaryotes genomes encode multiple chaperonin genes which can be divided into ? and ? subtypes. Unlike the homo-oligomeric chaperonins from bacteria and mitochondria, chloroplast chaperonins are more complex and exists as intricate hetero-oligomers containing both subtypes. The Group I chaperonin requires proper interaction with a detachable lid-like co-chaperonin in the presence of ATP and Mg2+ for substrate encapsulation and conformational transition. Besides the typical Cpn10-like co-chaperonin, a unique co-chaperonin consisting of two tandem Cpn10-like domains joined head-to-tail exists in chloroplasts. Since chloroplasts were proposed as sensors to various environmental stresses, this diversified chloroplast chaperonin system has the potential to adapt to complex conditions by accommodating specific substrates or through regulation at both the transcriptional and post-translational levels. In this review, we discuss recent progress on the unique structure and function of the chloroplast chaperonin system based on model organisms Chlamydomonas reinhardtii and Arabidopsis thaliana. Knowledge of the chloroplast chaperonin system may ultimately lead to successful reconstitution of eukaryotic Rubisco in vitro.

Dataset Information

Ring Separation Highlights the Protein-Folding Mechanism Used by the Phage EL-Encoded Chaperonin.

Publications

Ring Separation Highlights the Protein-Folding Mechanism Used by the Phage EL-Encoded Chaperonin.

Similar Datasets

OmicsDI is part of the ELIXIR infrastructure

Tweets