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Examines the effects of substrate binding and cofactor induction on glyceraldehyde 3-phosphate dehydrogenase (GADPH) from Escherichia coli. Limitation of the conformational changes in GADPH induced by cofactor binding; Steps involved in oxidative phosphorylation of glyceraldehyde 3-phosphate; Comparison between monoclinic apoenzyme and holoenzyme structures.

Examines the crystal structures of the disabled (Dab) homology domains of mouse Dab 1 and 2, mammalian homologues of Drosophila DAB. Confirmation of the structural determinants specific for the NPXY sequence and PtdIns-4,5-P[sub 2] binding through mutagenesis; Role played by simultaneous interaction of the rigid DAB homology domain with the NPXY sequence and PtdIns-4,5-P[sub 2] in the attachment of Dab proteins to the APP/lipoprotein receptors and phosphoinositide-rich membranes.

Nucleophosmin (NPM1) is a multifunctional phospho-protein with critical roles in ribosome biogenesis, tumor suppression, and nucleolar stress response. Here we show that the N-terminal oligomerization domain of NPM1 (Npm-N) exhibits structural polymorphism by populating conformational states ranging from a highly ordered, folded pentamer to a highly disordered monomer. The monomer- pentamer equilibrium is modulated by posttranslational modification and protein binding. Phosphorylation drives the equilibrium in favor of monomeric forms, and this effect can be reversed by Npm-N binding to its interaction partners. We have identified a short, arginine-rich linear motif in NPM1 binding partners that mediates Npm-N oligomerization. We propose that the diverse functional repertoire associated with NPM1 is controlled through a regulated unfolding mechanism signaled through posttranslational modifications and intermolecular interactions. [ABSTRACT FROM AUTHOR]