- 作者: Yi-Chien Fang, Mingyuan Cheng
- 作者服務機構: Institute of Genetics, School of Life Sciences, National Yang-Ming University, Taipei, Taiwan, ROC
- 中文摘要: --
- 英文摘要: HSP60 is an essential gene in Saccharomyces cerevisiae.The protein forms homotetradecameric double toroidcomplexes. The flexible C-terminal end of each subunit,which is hydrophobic in nature, protrudes inside the cen-tral cavity where protein folding occurs. In order to studythe functional role of the C-terminus of Hsp60, we gener-ated and characterized yeast strains expressing mutantsof Hsp60 proteins. Most of the yeast strains expressingHsp60 with C-terminal deletions grew normally, unlessthe deletion impaired the interaction between neighbor-ing subunits. The cells carrying Hsp60 mutants with anepitope of influenza hemagglutinin (HA) and T7 alone inthe C-terminal region grew normally, but the mutantcontaining both HA and T7 was unable to grow in nonfer-mentable carbon sources. In vitro biochemical assayswere performed using purified Hsp60 proteins. All themutants examined remained capable of interacting withHsp10 in a nucleotide-dependent manner. However,binding and/or refolding of denatured rhodanese be-came defective in most of the hsp60 mutants. Therefore,the hydrophobic C-terminal tail of Hsp60 plays an impor-tant role in the refolding of protein substrates, although itis flexible in structure.
- 中文關鍵字: --
- 英文關鍵字: Chaperonin, Hsp60, Molecular chaperone, Mutation, Protein folding, Rhodanese