title: Cloning, purification and characterization of the Caenorhabditis elegans small glutamine-rich tetratricopeptide repeat-containing protein.
abstract: We have cloned and expressed the putative Caenorhabditis elegans orthologue for small glutamine-rich tetratricopeptide repeat-containing protein, now assigned the gene name sgt-1 in the C. elegans genome database. Characterization of the purified protein by cross-linking, mass spectrometry and gel filtration experiments provides unambiguous evidence that SGT-1 forms homo-dimers in solution. The hydrodynamic dimensions of SGT-1 dimers in relation to their molecular weight suggest a protein with a low level of compactness and an extended conformation. Human SGT has been shown to interact with and regulate the activity of heat shock proteins Hsp70 and Hsp90 via a TPR domain mediated interaction. The SGT TPR domain (SGT-1-TPR, residues 100-226) was cloned, purified and shown by ITC and CD analysis to interact with the C-terminal peptides of Hsp70 and Hsp90 with comparable affinities although there is no evidence of a recently proposed coupled binding-folding mechanism for TPR domains.
authors.affiliation: School of Biological Sciences, University of Edinburgh, The King's Buildings, Mayfield Road, Edinburgh, EH9 3JR, UK.
authors.forename: Liam J
authors.initials: LJ
authors.lastname: Worrall
authors.forename: Martin A
authors.initials: MA
authors.lastname: Wear
authors.forename: Antony P
authors.initials: AP
authors.lastname: Page
authors.forename: Malcolm D
authors.initials: MD
authors.lastname: Walkinshaw
mesh_terms: D000595:Amino Acid Sequence; D000818:Animals; D017173:Caenorhabditis elegans; D029742:Caenorhabditis elegans Proteins / Q000737:chemistry* / Q000235:genetics / Q000302:isolation & purification; D002352:Carrier Proteins / Q000737:chemistry* / Q000235:genetics / Q000302:isolation & purification; D002942:Circular Dichroism; D003001:Cloning, Molecular; D019281:Dimerization; D018840:HSP70 Heat-Shock Proteins / Q000737:chemistry; D018841:HSP90 Heat-Shock Proteins / Q000737:chemistry; D008969:Molecular Sequence Data; D010455:Peptides / Q000737:chemistry; D025941:Protein Interaction Mapping; D017434:Protein Structure, Tertiary
chemical_list: D029742:Caenorhabditis elegans Proteins; D002352:Carrier Proteins; D018840:HSP70 Heat-Shock Proteins; D018841:HSP90 Heat-Shock Proteins; D010455:Peptides; C528722:SGT-1 protein, C elegans