1uo5
STRUCTURE BASED ENGINEERING OF INTERNAL MOLECULAR SURFACES OF FOUR HELIX BUNDLES
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OverviewOverview
Cavities and clefts are frequently important sites of interaction between, natural enzymes or receptors and their corresponding substrate or ligand, molecules and exemplify the types of molecular surfaces that would, facilitate engineering of artificial catalysts and receptors. Even so, structural characterizations of designed cavities are rare. To address, this issue, we performed a systematic study of the structural effects of, single-amino acid substitutions within the hydrophobic cores of tetrameric, coiled-coil peptides. Peptides containing single glycine, serine, alanine, or threonine amino acid substitutions at the buried L9, L16, L23, and I26, hydrophobic core positions of a GCN4-based sequence were synthesized and, studied by solution-phase and crystallographic techniques. All peptides, adopt the expected tetrameric state and contain tunnels or internal, cavities ranging in size from 80 to 370 A(3). Two closely related, sequences containing an L16G substitution, one of which adopts an, antiparallel configuration and one of which adopts a parallel, configuration, illustrate that cavities of different volumes and shapes, can be engineered from identical core substitutions. Finally, we, demonstrate that two of the peptides (L9G and L9A) bind the small molecule, iodobenzene when present during crystallization, leaving the general, peptide quaternary structure intact but altering the local peptide, conformation and certain superhelical parameters. These high-resolution, descriptions of varied molecular surfaces within solvent-occluded internal, cavities illustrate the breadth of design space available in even closely, related peptides and offer valuable models for the engineering of de novo, helical proteins.
About this StructureAbout this Structure
1UO5 is a Single protein structure of sequence from [1] with CL and PIH as ligands. Full crystallographic information is available from OCA.
ReferenceReference
Structure-based engineering of internal cavities in coiled-coil peptides., Yadav MK, Redman JE, Leman LJ, Alvarez-Gutierrez JM, Zhang Y, Stout CD, Ghadiri MR, Biochemistry. 2005 Jul 19;44(28):9723-32. PMID:16008357
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