PEPTIDE RECOGNITION BY PTB AND PDZ DOMAINS

Protein tyrosine binding (PTB) and 'post synaptic density disc-large t o-1' (PDZ) domains bind to short peptidic ligands by augmentation of o ne of the domain's beta sheets and other recognition mechanisms, The t wo domain classes have a superficial resemblance to each other, even t hough no sequential homology exists. The structural bases of the inter actions are well understood for the few domains now experimentally det ermined, and ligand-target pairs can probably be identified in favorab le cases by analogy with the known domains. For both PTB and PDZ class es, functional activities are still not fully defined: it is possible that these domain classes, along with pleckstrin homology domains, hav e multiple roles. (C) Current Biology Ltd ISSN 0959-440X.