This work presents the crystal structure of the C-terminal 10 kDa- sub-domain from C. elegans Hsp70. Despite a high degree of sequence identity, the C. elegans domain is shown to adopt a conformation distinct from the rat crystal structure, consistent with the more distantly related bacterial homologous. Comparison with the rat structure reveals an intriguing putative domain-swap dimerisation mechanism though the isolated C. elegans domain was found to exist exclusively as a monomer in solution. A previous study identified two TPR domain containing C. elegans putative proteins predicted to interact with Hsp90. These proteins were identified as the C. elegans homologues for small glutamine-rich TPR containing protein (SGT) and Hsp70/Hsp90 organising protein (HOP). These proteins have been successfully cloned, expressed and purified. SGT forms homo-dimers in solution. Its hydrodynamic dimensions in relation to its molecular weight suggest a protein with a low level of compactness and an extended conformation. SGT interacts with the C-terminal peptides from both Hsp70 and Hsp90 with equal affinities. Studies on C. elegans HOP suggested it might exist as a dimer in solution. In addition, a tight binding interaction was demonstrated with human and C. elegans Hsp90 homologues. A thorough search of the complete C. elegans proteome and genome was performed to identify the complete repertoire of TPR domain containing proteins likely to interact with Hsp70 or Hsp90. A profile HMM based search of the published C. elegans protein and DNA databases identified 12 proteins; nine of which are homologues of proteins known to interact with Hsp70 or Hsp90. The remaining three are uncharacterised putative proteins and represent targets for further study.