3agz
From Proteopedia
Crystal structure of human Hsp40 Hdj1 peptide-binding domain complexed with a C-terminal peptide of Hsp70
Structural highlights
Function[DNJB1_HUMAN] Interacts with HSP70 and can stimulate its ATPase activity. Stimulates the association between HSC70 and HIP. [HSP7C_HUMAN] Acts as a repressor of transcriptional activation. Inhibits the transcriptional coactivator activity of CITED1 on Smad-mediated transcription. Chaperone. Component of the PRP19-CDC5L complex that forms an integral part of the spliceosome and is required for activating pre-mRNA splicing. May have a scaffolding role in the spliceosome assembly as it contacts all other components of the core complex.[1] Publication Abstract from PubMedHeat shock protein (Hsp) 40s play essential roles in cellular processes by cooperating with Hsp70 proteins. Hsp40 proteins recognize non-native polypeptides, deliver these peptides to Hsp70 proteins, and stimulate the ATPase activity of Hsp70 proteins to facilitate the correct folding of the polypeptides. We have determined the crystal structures of the C-terminal peptide-binding domain of human Hsp40 Hdj1 (CTD) and of its complex with the C-terminal octapeptide of human Hsp70, (634')GPTIEEVD(641'). CTD exists as a twisted, horseshoe-shaped homodimer. The protomer consists of two domains, I and II, with similar topologies. The octapeptides are located in two sites, 1 and 2, of domain I. In site 1, the octapeptide forms an antiparallel beta-sheet with CTD. The negatively charged residues of the EEVD motif in the octapeptide form electrostatic interactions with the positively charged Lys residues of CTD. The Ile side chain of the octapeptide fits into the narrow concave formed by the hydrophobic residues of CTD. In site 2, the octapeptide also forms an antiparallel beta-sheet with CTD, and the EEVD motif forms electrostatic interactions. The side chains of Pro and Ile of the octapeptide interact with the hydrophobic surface region of CTD site 2, which is broader and shallower than the concave binding region of site 1. This region seems to be capable of binding hydrophobic side chains that are bulkier than the Ile side chain. The roles of these two peptide-binding sites of Hdj1 are discussed. Peptide-binding sites as revealed by the crystal structures of the human Hsp40 Hdj1 C-terminal domain in complex with the octapeptide from human Hsp70.,Suzuki H, Noguchi S, Arakawa H, Tokida T, Hashimoto M, Satow Y Biochemistry. 2010 Oct 5;49(39):8577-84. Epub 2010 Sep 9. PMID:20809635[2] From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine. References
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