Super Spy variants implicate flexibility in chaperone action
Shu Quan,
Lili Wang,
Evgeniy V Petrotchenko,
Karl AT Makepeace,
Scott Horowitz,
Jianyi Yang,
Yang Zhang,
Christoph H Borchers,
James CA Bardwell
Affiliations
Shu Quan
Department of Molecular, Cellular, and Developmental Biology, Howard Hughes Medical Institute, University of Michigan, Ann Arbor, United States
Lili Wang
Department of Molecular, Cellular, and Developmental Biology, Howard Hughes Medical Institute, University of Michigan, Ann Arbor, United States
Evgeniy V Petrotchenko
Department of Biochemistry and Microbiology, Genome British Columbia Proteomics Centre, University of Victoria, Victoria, Canada
Karl AT Makepeace
Department of Biochemistry and Microbiology, Genome British Columbia Proteomics Centre, University of Victoria, Victoria, Canada
Scott Horowitz
Department of Molecular, Cellular, and Developmental Biology, Howard Hughes Medical Institute, University of Michigan, Ann Arbor, United States
Jianyi Yang
Department of Computational Medicine and Bioinformatics, University of Michigan, Ann Arbor, United States
Yang Zhang
Department of Computational Medicine and Bioinformatics, University of Michigan, Ann Arbor, United States
Christoph H Borchers
Department of Biochemistry and Microbiology, Genome British Columbia Proteomics Centre, University of Victoria, Victoria, Canada
James CA Bardwell
Department of Molecular, Cellular, and Developmental Biology, Howard Hughes Medical Institute, University of Michigan, Ann Arbor, United States; Department of Biological Chemistry, University of Michigan, Ann Arbor, United States
Experimental study of the role of disorder in protein function is challenging. It has been proposed that proteins utilize disordered regions in the adaptive recognition of their various binding partners. However apart from a few exceptions, defining the importance of disorder in promiscuous binding interactions has proven to be difficult. In this paper, we have utilized a genetic selection that links protein stability to antibiotic resistance to isolate variants of the newly discovered chaperone Spy that show an up to 7 fold improved chaperone activity against a variety of substrates. These “Super Spy” variants show tighter binding to client proteins and are generally more unstable than is wild type Spy and show increases in apparent flexibility. We establish a good relationship between the degree of their instability and the improvement they show in their chaperone activity. Our results provide evidence for the importance of disorder and flexibility in chaperone function.
