Structural Basis of the Substrate Specificity of Bifunctional Isocitrate Dehydrogenase Kinase/Phosphatase

Autor: Adam J. Stein, Susan P. Yates, Cassie M. Bryan, Jimin Zheng, Peter J. Myler, Thomas E. Edwards, Wesley C. Van Voorhis, Zongchao Jia, Lance Stewart
Rok vydání: 2011
Předmět:
Zdroj: Biochemistry. 50:8103-8106
ISSN: 1520-4995
0006-2960
DOI: 10.1021/bi200809p
Popis: Isocitrate dehydrogenase kinase/phosphatase (AceK) regulates entry into the glyoxylate bypass by reversibly phosphorylating isocitrate dehydrogenase (ICDH). On the basis of the recently determined structure of the AceK-ICDH complex from Escherichia coli, we have classified the structures of homodimeric NADP(+)-ICDHs to rationalize and predict which organisms likely contain substrates for AceK. One example is Burkholderia pseudomallei (Bp). Here we report a crystal structure of Bp-ICDH that exhibits the necessary structural elements required for AceK recognition. Kinetic analyses provided further confirmation that Bp-ICDH is a substrate for AceK. We conclude that the highly stringent AceK binding sites on ICDH are maintained only in Gram-negative bacteria.
Databáze: OpenAIRE