A glutamate switch controls voltage-sensitive phosphatase function

Lijun Liu, Susy C. Kohout, Qiang Xu, Simone Müller, Christopher R. Kimberlin, Ehud Y. Isacoff, Daniel L. Minor

Research output: Contribution to journalArticlepeer-review

36 Scopus citations


The Ciona intestinalis voltage-sensing phosphatase (Ci-VSP) couples a voltage-sensing domain (VSD) to a lipid phosphatase that is similar to the tumor suppressor PTEN. How the VSD controls enzyme function has been unclear. Here, we present high-resolution crystal structures of the Ci-VSP enzymatic domain that reveal conformational changes in a crucial loop, termed the 'gating loop', that controls access to the active site by a mechanism in which residue Glu411 directly competes with substrate. Structure-based mutations that restrict gating loop conformation impair catalytic function and demonstrate that Glu411 also contributes to substrate selectivity. Structure-guided mutations further define an interaction between the gating loop and linker that connects the phosphatase to the VSD for voltage control of enzyme activity. Together, the data suggest that functional coupling between the gating loop and the linker forms the heart of the regulatory mechanism that controls voltage-dependent enzyme activation.

Original languageEnglish (US)
Pages (from-to)633-641
Number of pages9
JournalNature Structural and Molecular Biology
Issue number6
StatePublished - Jun 2012
Externally publishedYes

All Science Journal Classification (ASJC) codes

  • Structural Biology
  • Molecular Biology


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