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The chaperonin GroEL binds to late-folding non-native conformations present in native Escherichia coli and murine dihydrofolate reductases.
J Mol Biol. 1999 Jan 29; 285(4):1777-88.JM

Abstract

Dihydrofolate reductases from mouse (MuDHFR) or Escherichia coli (EcDHFR) are shown to refold via several intermediate forms, each of which can bind to the chaperonin GroEL. When stable complexes with GroEL are formed, they consist of late-folding intermediates. In addition, we find that late-folding intermediates that are present in the native enzyme bind to GroEL. For the E. coli and murine proteins, the extent of protein bound increases as the temperature is increased from 8 degreesC to 42 degreesC, at which temperature either protein is completely bound as the last (EcDHFR) or the last two (MuDHFR) folding intermediate(s). Thus for EcDHFR, the binding is transient at low temperature (<30 degreesC) and stable at high temperature (>35 degreesC). For MuDHFR, complex formation appears less temperature dependent. In general, the data demonstrate that the overall binding free energy for the interaction of GroEL with native DHFR is the sum of the free energy for the first step in DHFR unfolding, which is unfavorable, and the free energy of binding the non-native conformation, which is favorable. For EcDHFR, this results in an overall binding free energy that is unfavorable below 30 degreesC. Over the temperature range of 8 degreesC to 42 degreesC, GroEL binds MuDHFR more tightly than EcDHFR, due partially to a small free energy difference between two pre-existing non-native conformations of MuDHFR, resulting in binding to more than one folding intermediate.

Authors+Show Affiliations

Department of Biochemistry and Molecular Biophysics, Washington University School of Medicine, St. Louis, MO, 63110, USA.No affiliation info available

Pub Type(s)

Comparative Study
Journal Article
Research Support, U.S. Gov't, P.H.S.

Language

eng

PubMed ID

9917411

Citation

Clark, A C., and C Frieden. "The Chaperonin GroEL Binds to Late-folding Non-native Conformations Present in Native Escherichia Coli and Murine Dihydrofolate Reductases." Journal of Molecular Biology, vol. 285, no. 4, 1999, pp. 1777-88.
Clark AC, Frieden C. The chaperonin GroEL binds to late-folding non-native conformations present in native Escherichia coli and murine dihydrofolate reductases. J Mol Biol. 1999;285(4):1777-88.
Clark, A. C., & Frieden, C. (1999). The chaperonin GroEL binds to late-folding non-native conformations present in native Escherichia coli and murine dihydrofolate reductases. Journal of Molecular Biology, 285(4), 1777-88.
Clark AC, Frieden C. The Chaperonin GroEL Binds to Late-folding Non-native Conformations Present in Native Escherichia Coli and Murine Dihydrofolate Reductases. J Mol Biol. 1999 Jan 29;285(4):1777-88. PubMed PMID: 9917411.
* Article titles in AMA citation format should be in sentence-case
TY - JOUR T1 - The chaperonin GroEL binds to late-folding non-native conformations present in native Escherichia coli and murine dihydrofolate reductases. AU - Clark,A C, AU - Frieden,C, PY - 1999/1/26/pubmed PY - 1999/1/26/medline PY - 1999/1/26/entrez SP - 1777 EP - 88 JF - Journal of molecular biology JO - J Mol Biol VL - 285 IS - 4 N2 - Dihydrofolate reductases from mouse (MuDHFR) or Escherichia coli (EcDHFR) are shown to refold via several intermediate forms, each of which can bind to the chaperonin GroEL. When stable complexes with GroEL are formed, they consist of late-folding intermediates. In addition, we find that late-folding intermediates that are present in the native enzyme bind to GroEL. For the E. coli and murine proteins, the extent of protein bound increases as the temperature is increased from 8 degreesC to 42 degreesC, at which temperature either protein is completely bound as the last (EcDHFR) or the last two (MuDHFR) folding intermediate(s). Thus for EcDHFR, the binding is transient at low temperature (<30 degreesC) and stable at high temperature (>35 degreesC). For MuDHFR, complex formation appears less temperature dependent. In general, the data demonstrate that the overall binding free energy for the interaction of GroEL with native DHFR is the sum of the free energy for the first step in DHFR unfolding, which is unfavorable, and the free energy of binding the non-native conformation, which is favorable. For EcDHFR, this results in an overall binding free energy that is unfavorable below 30 degreesC. Over the temperature range of 8 degreesC to 42 degreesC, GroEL binds MuDHFR more tightly than EcDHFR, due partially to a small free energy difference between two pre-existing non-native conformations of MuDHFR, resulting in binding to more than one folding intermediate. SN - 0022-2836 UR - https://www.unboundmedicine.com/medline/citation/9917411/The_chaperonin_GroEL_binds_to_late_folding_non_native_conformations_present_in_native_Escherichia_coli_and_murine_dihydrofolate_reductases_ L2 - https://linkinghub.elsevier.com/retrieve/pii/S0022-2836(98)92403-2 DB - PRIME DP - Unbound Medicine ER -