Functional analysis of Group 2 chaperonins from archaeal species in E. coli

[摘要] The chaperonin proteins form a ubiquitous family of molecular chaperones and are absolutely required for correct folding or assembly of a subset of proteins in the cell. They are divided into two groups based on phylogeny: Group 1 found in bacteria and eukaryotic-organelles and Group 2 found in eukaryotic-cytoplasma and archaea. The two groups share a significant degree of conservation but differ in structure and mechanism and are believed to have evolved to serve specific client proteins. Using archaeal chaperonin from M. maripaludis (MmCCT) as a representative, we report here for the first time that a Group 2 chaperonin can partially replace the function of a Group 1 chaperonin from E. coli (GroEL). We have also identified and characterized two functional variants of MmCCT that show better GroEL complementation and have utilized them for a preliminary mutational analysis of potential client binding residues of MmCCT. We further demonstrate an initiative using a tagging approach for identification of bacterial proteins that interact with MmCCT in vivo. We suggest that our findings provide a novel platform for genetic dissection of MmCCT using a comparatively simple host, E. coli, which in turn can help identify properties of this archaeal chaperonin and provide insights for structure-function co-relations of Group 2 chaperonins in general.

[发布机构] University:University of Birmingham;Department:School of Biosciences

[关键词] Q Science;QH Natural history;QH301 Biology