Trigger factor from Thermus thermophilus is a Zn2+-dependent chaperone.
The ribosome-associated chaperone trigger factor (TF) of Escherichia coli interacts with a variety of newly synthesized polypeptides to assist their correct folding. Here, we report that the TF of thermophilic eubacterium, Thermus thermophilus, arrested spontaneous folding of green fluorescent protein by forming a 1:1 binary complex. The complex was isolable by gel-filtration but was shown to be dynamic because green fluorescent protein was released by alpha-casein in large excess. Unexpectedly, EDTA completely abolished the folding-arrest activity of TF, and analysis revealed that the TF from our preparation contained approximately 0.5 mol Zn2+/mol TF. The folding-arrest activity of TF that was saturated with Zn2+ (approximately 1 mol/mol TF) was twice as efficient as that of untreated TF. Thus, chaperone activity of thermophilic TF is Zn2+-dependent.
Suno
Ryoji
R
Chemical Resources Laboratory, Tokyo Institute of Technology, 4259 Nagatsuta, Yokohama 226-8503, Japan.
Taguchi
Hideki
H
Masui
Ryoji
R
Odaka
Masafumi
M
Yoshida
Masasuke
M
D000595:Amino Acid Sequence; D002850:Chromatography, Gel; D004305:Dose-Response Relationship, Drug; D004492:Edetic Acid / Q000494:pharmacology; D029968:Escherichia coli Proteins / Q000378:metabolism / Q000502:physiology*; D049452:Green Fluorescent Proteins; D008164:Luminescent Proteins / Q000378:metabolism; D008969:Molecular Sequence Data; D019696:Peptidylprolyl Isomerase / Q000378:metabolism / Q000502:physiology*; D011485:Protein Binding; D017510:Protein Folding; D017386:Sequence Homology, Amino Acid; D016963:Thermus thermophilus / Q000378:metabolism*; D013997:Time Factors; D015032:Zinc / Q000737:chemistry* / Q000378:metabolism
D029968:Escherichia coli Proteins; D008164:Luminescent Proteins; D049452:Green Fluorescent Proteins; D004492:Edetic Acid; C403324:trigger factor, E coli; D019696:Peptidylprolyl Isomerase; D015032:Zinc