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Characterization of metal binding of bifunctional kinase/phosphatase AceK and implication in activity modulation.
Sci Rep. 2019 06 24; 9(1):9198.SR

Abstract

A unique bifunctional enzyme, isocitrate dehydrogenase kinase/phosphatase (AceK) regulates isocitrate dehydrogenase (IDH) by phosphorylation and dephosphorylation in response to nutrient availability. Herein we report the crystal structure of AceK in complex with ADP and Mn2+ ions. Although the overall structure is similar to the previously reported structures which contain only one Mg2+ ion, surprisingly, two Mn2+ ions are found in the catalytic center of the AceK-Mn2+ structure. Our enzymatic assays demonstrate that AceK-Mn2+ showed higher phosphatase activity than AceK-Mg2+, whereas the kinase activity was relatively unaffected. We created mutants of AceK for all metal-coordinating residues. The phosphatase activities of these mutants were significantly impaired, suggesting the pivotal role of the binuclear (M1-M2) core in AceK phosphatase catalysis. Moreover, we have studied the interactions of Mn2+ and Mg2+ with wild-type and mutant AceK and found that the number of metal ions bound to AceK is in full agreement with the crystal structures. Combined with the enzymatic results, we demonstrate that AceK exhibits phosphatase activity in the presence of two, but not one, Mn2+ ions, similar to PPM phosphatases. Taken together, we suggest that metal ions help AceK to balance and fine tune its kinase and phosphatase activities.

Authors+Show Affiliations

College of Chemistry, Beijing Normal University, Beijing, 100875, China.College of Chemistry, Beijing Normal University, Beijing, 100875, China.College of Chemistry, Beijing Normal University, Beijing, 100875, China.College of Chemistry, Beijing Normal University, Beijing, 100875, China.College of Chemistry, Beijing Normal University, Beijing, 100875, China. jimin_z@bnu.edu.cn.Department of Biomedical and Molecular Sciences, Queen's University, Kingston, Ontario, K7L3N6, Canada. jia@queensu.ca.

Pub Type(s)

Journal Article
Research Support, Non-U.S. Gov't

Language

eng

PubMed ID

31235769

Citation

Zhang, Xiaoying, et al. "Characterization of Metal Binding of Bifunctional Kinase/phosphatase AceK and Implication in Activity Modulation." Scientific Reports, vol. 9, no. 1, 2019, p. 9198.
Zhang X, Shen Q, Lei Z, et al. Characterization of metal binding of bifunctional kinase/phosphatase AceK and implication in activity modulation. Sci Rep. 2019;9(1):9198.
Zhang, X., Shen, Q., Lei, Z., Wang, Q., Zheng, J., & Jia, Z. (2019). Characterization of metal binding of bifunctional kinase/phosphatase AceK and implication in activity modulation. Scientific Reports, 9(1), 9198. https://doi.org/10.1038/s41598-019-45704-z
Zhang X, et al. Characterization of Metal Binding of Bifunctional Kinase/phosphatase AceK and Implication in Activity Modulation. Sci Rep. 2019 06 24;9(1):9198. PubMed PMID: 31235769.
* Article titles in AMA citation format should be in sentence-case
TY - JOUR T1 - Characterization of metal binding of bifunctional kinase/phosphatase AceK and implication in activity modulation. AU - Zhang,Xiaoying, AU - Shen,Qingya, AU - Lei,Zhen, AU - Wang,Qianyi, AU - Zheng,Jimin, AU - Jia,Zongchao, Y1 - 2019/06/24/ PY - 2019/01/14/received PY - 2019/06/11/accepted PY - 2019/6/26/entrez PY - 2019/6/27/pubmed PY - 2020/10/21/medline SP - 9198 EP - 9198 JF - Scientific reports JO - Sci Rep VL - 9 IS - 1 N2 - A unique bifunctional enzyme, isocitrate dehydrogenase kinase/phosphatase (AceK) regulates isocitrate dehydrogenase (IDH) by phosphorylation and dephosphorylation in response to nutrient availability. Herein we report the crystal structure of AceK in complex with ADP and Mn2+ ions. Although the overall structure is similar to the previously reported structures which contain only one Mg2+ ion, surprisingly, two Mn2+ ions are found in the catalytic center of the AceK-Mn2+ structure. Our enzymatic assays demonstrate that AceK-Mn2+ showed higher phosphatase activity than AceK-Mg2+, whereas the kinase activity was relatively unaffected. We created mutants of AceK for all metal-coordinating residues. The phosphatase activities of these mutants were significantly impaired, suggesting the pivotal role of the binuclear (M1-M2) core in AceK phosphatase catalysis. Moreover, we have studied the interactions of Mn2+ and Mg2+ with wild-type and mutant AceK and found that the number of metal ions bound to AceK is in full agreement with the crystal structures. Combined with the enzymatic results, we demonstrate that AceK exhibits phosphatase activity in the presence of two, but not one, Mn2+ ions, similar to PPM phosphatases. Taken together, we suggest that metal ions help AceK to balance and fine tune its kinase and phosphatase activities. SN - 2045-2322 UR - https://www.unboundmedicine.com/medline/citation/31235769/Characterization_of_metal_binding_of_bifunctional_kinase/phosphatase_AceK_and_implication_in_activity_modulation_ DB - PRIME DP - Unbound Medicine ER -