Please use this identifier to cite or link to this item: http://repositorio.unicamp.br/jspui/handle/REPOSIP/199660
Type: Artigo de periódico
Title: Central Domain Deletions Affect The Saxs Solution Structure And Function Of Yeast Hsp40 Proteins Sis1 And Ydj1.
Author: Silva, Julio C
Borges, Julio C
Cyr, Douglas M
Ramos, Carlos Hi
Torriani, Iris L
Abstract: Ydj1 and Sis1 are structurally and functionally distinct Hsp40 proteins of the yeast cytosol. Sis1 is an essential gene whereas the ydj1 gene is essential for growth at elevated temperatures and cannot complement sis1 gene deletion. Truncated polypeptides capable of complementing the sis1 gene deletion comprise the J-domain of either Sis1 or Ydj1 connected to the G/F region of Sis1 (but not Ydj1). Sis1 mutants in which the G/F was deleted but G/M maintained were capable of complementing the sis1 gene deletion. To investigate the relevance of central domains on the structure and function of Ydj1 and Sis1 we prepared Sis1 constructs deleting specific domains. The mutants had decreased affinity for heated luciferase but were equally capable of stimulating ATPase activity of Hsp70. Detailed low resolution structures were obtained and the overall flexibility of Hsp40 and its mutants were assessed using SAXS methods. Deletion of either the G/M or the G/M plus CTDI domains had little impact on the quaternary structure of Sis1 analyzed by the SAXS technique. However, deletion of the ZFLR-CTDI changed the relative position of the J-domains in Ydj1 in such a way that they ended up resembling that of Sis1. The results revealed that the G/F and G/M regions are not the only flexible domains. All model structures exhibit a common clamp-like conformation. Our results suggest that the central domains, previously appointed as important features for substrate binding, are also relevant keeping the J-domains in their specific relative positions. The clamp-like architecture observed seems also to be favorable to the interactions of Hsp40 with Hsp70.
Subject: Circular Dichroism
Hsp40 Heat-shock Proteins
Models, Molecular
Protein Structure, Tertiary
Recombinant Proteins
Saccharomyces Cerevisiae
Saccharomyces Cerevisiae Proteins
Scattering, Small Angle
X-ray Diffraction
Rights: fechado
Identifier DOI: 10.1186/1472-6807-11-40
Address: http://www.ncbi.nlm.nih.gov/pubmed/22011374
Date Issue: 2011
Appears in Collections:Unicamp - Artigos e Outros Documentos

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