Tags

Type your tag names separated by a space and hit enter

Phosphorylation destabilizes the amino-terminal domain of enzyme I of the Escherichia coli phosphoenolpyruvate:sugar phosphotransferase system.
Biochemistry. 1998 May 12; 37(19):6718-26.B

Abstract

Thermal stabilities of enzyme I (63 562 M(r) subunit, in the Escherichia coli phosphoenolpyruvate (PEP):sugar phosphotransferase system (PTS), and a cloned amino-terminal domain of enzyme I (EIN; 28 346 Mr) were investigated by differential scanning calorimetry (DSC) and far-UV circular dichroism (CD) at pH 7.5. EIN expressed in a delta pts E. coli strain showed a single, reversible, two-state transition with Tm = 57 degrees C and an unfolding enthalpy of approximately 140 kcal/mol. In contrast, monomeric EIN expressed in a wild-type strain (pts+) had two endotherms with Tm congruent with 50 and 57 degrees C and overall delta H = 140 kcal/mol and was converted completely to the more stable form after five DSC scans from 10 to 75 degrees C (without changes in CD: approximately 58% alpha-helices). Thermal conversion to a more stable form was correlated with dephosphorylation of EIN by mass spectral analysis. Dephospho-enzyme I (monomer right arrow over left arrow dimer) exhibited endotherms for C- and N-terminal domain unfolding with Tm = 41 and 54 degrees C, respectively. Thermal unfolding of the C-terminal domain occurred over a broad temperature range (approximately 30-50 degrees C), was scan rate- and concentration-dependent, coincident with a light scattering decrease and Trp residue exposure, and independent of phosphorylation. Reversible thermal unfolding of the nonphosphorylated N-terminal domain was more cooperative, occurring from 50 to 60 degrees C. DSC of partially phosphorylated enzyme I indicated that the amino-terminal domain was destabilized by phosphorylation (from Tm = 54 to approximately 48 degrees C). A decrease in conformational stability of the amino-terminal domain of enzyme I produced by phosphorylation of the active-site His 189 has the physiological consequence of promoting phosphotransfer to the phosphocarrier protein, HP(r).

Authors+Show Affiliations

Section on Protein Chemistry, Laboratory of Biochemistry, National Heart, Lung, and Blood Institute, Bethesda, Maryland 20892, USA.No affiliation info availableNo affiliation info availableNo affiliation info availableNo affiliation info availableNo affiliation info available

Pub Type(s)

Journal Article

Language

eng

PubMed ID

9578555

Citation

Nosworthy, N J., et al. "Phosphorylation Destabilizes the Amino-terminal Domain of Enzyme I of the Escherichia Coli Phosphoenolpyruvate:sugar Phosphotransferase System." Biochemistry, vol. 37, no. 19, 1998, pp. 6718-26.
Nosworthy NJ, Peterkofsky A, König S, et al. Phosphorylation destabilizes the amino-terminal domain of enzyme I of the Escherichia coli phosphoenolpyruvate:sugar phosphotransferase system. Biochemistry. 1998;37(19):6718-26.
Nosworthy, N. J., Peterkofsky, A., König, S., Seok, Y. J., Szczepanowski, R. H., & Ginsburg, A. (1998). Phosphorylation destabilizes the amino-terminal domain of enzyme I of the Escherichia coli phosphoenolpyruvate:sugar phosphotransferase system. Biochemistry, 37(19), 6718-26.
Nosworthy NJ, et al. Phosphorylation Destabilizes the Amino-terminal Domain of Enzyme I of the Escherichia Coli Phosphoenolpyruvate:sugar Phosphotransferase System. Biochemistry. 1998 May 12;37(19):6718-26. PubMed PMID: 9578555.
* Article titles in AMA citation format should be in sentence-case
TY - JOUR T1 - Phosphorylation destabilizes the amino-terminal domain of enzyme I of the Escherichia coli phosphoenolpyruvate:sugar phosphotransferase system. AU - Nosworthy,N J, AU - Peterkofsky,A, AU - König,S, AU - Seok,Y J, AU - Szczepanowski,R H, AU - Ginsburg,A, PY - 1998/6/6/pubmed PY - 1998/6/6/medline PY - 1998/6/6/entrez SP - 6718 EP - 26 JF - Biochemistry JO - Biochemistry VL - 37 IS - 19 N2 - Thermal stabilities of enzyme I (63 562 M(r) subunit, in the Escherichia coli phosphoenolpyruvate (PEP):sugar phosphotransferase system (PTS), and a cloned amino-terminal domain of enzyme I (EIN; 28 346 Mr) were investigated by differential scanning calorimetry (DSC) and far-UV circular dichroism (CD) at pH 7.5. EIN expressed in a delta pts E. coli strain showed a single, reversible, two-state transition with Tm = 57 degrees C and an unfolding enthalpy of approximately 140 kcal/mol. In contrast, monomeric EIN expressed in a wild-type strain (pts+) had two endotherms with Tm congruent with 50 and 57 degrees C and overall delta H = 140 kcal/mol and was converted completely to the more stable form after five DSC scans from 10 to 75 degrees C (without changes in CD: approximately 58% alpha-helices). Thermal conversion to a more stable form was correlated with dephosphorylation of EIN by mass spectral analysis. Dephospho-enzyme I (monomer right arrow over left arrow dimer) exhibited endotherms for C- and N-terminal domain unfolding with Tm = 41 and 54 degrees C, respectively. Thermal unfolding of the C-terminal domain occurred over a broad temperature range (approximately 30-50 degrees C), was scan rate- and concentration-dependent, coincident with a light scattering decrease and Trp residue exposure, and independent of phosphorylation. Reversible thermal unfolding of the nonphosphorylated N-terminal domain was more cooperative, occurring from 50 to 60 degrees C. DSC of partially phosphorylated enzyme I indicated that the amino-terminal domain was destabilized by phosphorylation (from Tm = 54 to approximately 48 degrees C). A decrease in conformational stability of the amino-terminal domain of enzyme I produced by phosphorylation of the active-site His 189 has the physiological consequence of promoting phosphotransfer to the phosphocarrier protein, HP(r). SN - 0006-2960 UR - https://www.unboundmedicine.com/medline/citation/9578555/Phosphorylation_destabilizes_the_amino_terminal_domain_of_enzyme_I_of_the_Escherichia_coli_phosphoenolpyruvate:sugar_phosphotransferase_system_ L2 - https://doi.org/10.1021/bi980126x DB - PRIME DP - Unbound Medicine ER -