Role of electrostatic interactions in PDZ domain ligand recognition

Baruch Z. Harris, Francis W. Lau, Naoaki Fujii, R. Kiplin Guy, Wendell A. Lim

Research output: Contribution to journalArticlepeer-review

42 Scopus citations


PDZ domains are protein - protein interaction modules that normally recognize short C-terminal peptides. The apparent requirement for a ligand with a free terminal carboxylate group has led to the proposal that electrostatic interactions with the terminus play a significant role in recognition. However, this model has been called into question by the more recent finding, that PDZ domains can recognize some internal peptide motifs that occur within a specific secondary structure context. Although these motifs bind at the same interface, they lack a terminal charge. Here we have investigated the role of electrostatics in PDZ-mediated recognition in the mouse α1-syntrophin PDZ domain by examining the salt dependence of binding to both terminal and internal ligands and the effects of mutating a conserved basic residue previously proposed to play a role in electrostatic recognition. These studies indicate that direct electrostatic interactions with the peptide terminus do not play a significant energetic role in binding. Additional chemical modification studies of the peptide terminus support a model in which steric and hydrogen bonding complementarity play a primary role in recognition specificity. Peptides with a free carboxy terminus, or presented within a specific structural context, can satisfy these requirements.

Original languageEnglish
Pages (from-to)2797-2805
Number of pages9
Issue number10
StatePublished - Mar 18 2003

ASJC Scopus subject areas

  • Biochemistry


Dive into the research topics of 'Role of electrostatic interactions in PDZ domain ligand recognition'. Together they form a unique fingerprint.

Cite this