Any feedback?
Please rate this page
(literature.php)
(0/150)

BRENDA support

Literature summary for 7.4.2.3 extracted from

  • Becker, D.; Krayl, M.; Strub, A.; Li, Y.; Mayer, M.P.; Voos, W.
    Impaired interdomain communication in mitochondrial Hsp70 results in the loss of inward-directed translocation force (2009), J. Biol. Chem., 284, 2934-2946.
    View publication on PubMed

Cloned(Commentary)

Cloned (Comment) Organism
SSC1 expression in Saccharomyces cerevisiae Saccharomyces cerevisiae

Protein Variants

Protein Variants Comment Organism
E240A/V241A the mutation is supposed to affect both a cluster of charge interactions with Lys546 and Arg437 of the mtHsp70 substrate-binding domain, as well as hydrophobic interactions at the interface between the two Hsp70 domains, e.g. Ala542 within alpha-helix A of the substrate-binding domain. Lethal mutation due to a defect in allosteric regulation, phenotype, overview. No complementation of a ssc1 null mutant Saccharomyces cerevisiae
additional information generation of specific mtHsp70 mutations located within or close to the interface between the nucleotide-binding and the substrate-binding domains. Mitochondria isolated from mtHsp70 mutants display severely reduced import efficiencies in vitro. Two of the mutants exhibit strong growth defects in vivo and are significantly impaired in the generation of an inward-directed, ATP-dependent import force on precursor proteins in transit. Mutants show defects in the transfer of conformational signals to the substrate-binding domain, resulting in a prolonged and enhanced interaction with imported substrate proteins. Furthermore, interference with the allosteric mechanism results in defects of translocation-specific partner protein interaction Saccharomyces cerevisiae
N175A/D176A the mutation abolishes a salt bridge that is formed between Asp176 of the nucleotide-binding domain and Lys544 of the substrate-binding domain. The mutant shows a temperature-sensitive phenotype with defect growth at 30°C due to a defect in allosteric regulation, phenotype, overview. No complementation of a ssc1 null mutant Saccharomyces cerevisiae
Y173A residue Tyr173, that is exposed on the molecular surface and located close to both the nucleotide-binding site and the putative domain interface. The mutant displays normal growth that is indistinguishable from cells expressing wild-type Ssc1. Complementation of a ssc1 null mutant Saccharomyces cerevisiae

Localization

Localization Comment Organism GeneOntology No. Textmining
mitochondrion
-
Saccharomyces cerevisiae 5739
-

Metals/Ions

Metals/Ions Comment Organism Structure
K+ activates Saccharomyces cerevisiae
Mg2+ required Saccharomyces cerevisiae

Natural Substrates/ Products (Substrates)

Natural Substrates Organism Comment (Nat. Sub.) Natural Products Comment (Nat. Pro.) Rev. Reac.
ATP + H2O Saccharomyces cerevisiae the essential mitochondrial Hsp70 is required for the import of mitochondrial preproteins into the matrix compartment. The translocation, specific activity of mitochondrial Hsp70 is coordinated by its interaction with specific partner proteins, forming the import motor complex that provides the energy for unfolding and complete translocation of precursor polypeptide chains. Impaired interdomain communication in mitochondrial Hsp70 results in the loss of inward-directed translocation force ADP + phosphate
-
?
additional information Saccharomyces cerevisiae even a partial disruption of the interdomain communication in the mtHsp70 chaperone results in an almost complete breakdown of its translocation-driving properties ?
-
?

Organism

Organism UniProt Comment Textmining
Saccharomyces cerevisiae
-
-
-

Purification (Commentary)

Purification (Comment) Organism
isolation of mitochondria from Saccharomyces cerevisiae cells recombinantly expressing His-tagged mtHsp70, and further purification by nickel affinity chromatography Saccharomyces cerevisiae

Specific Activity [micromol/min/mg]

Specific Activity Minimum [µmol/min/mg] Specific Activity Maximum [µmol/min/mg] Comment Organism
additional information
-
quantitative analysis of ATP binding activity of recombinant mtHsp70 Saccharomyces cerevisiae

Substrates and Products (Substrate)

Substrates Comment Substrates Organism Products Comment (Products) Rev. Reac.
ATP + H2O the essential mitochondrial Hsp70 is required for the import of mitochondrial preproteins into the matrix compartment. The translocation, specific activity of mitochondrial Hsp70 is coordinated by its interaction with specific partner proteins, forming the import motor complex that provides the energy for unfolding and complete translocation of precursor polypeptide chains. Impaired interdomain communication in mitochondrial Hsp70 results in the loss of inward-directed translocation force Saccharomyces cerevisiae ADP + phosphate
-
?
ATP + H2O Hsp70-type chaperones show nucleotide-regulated affinity to polypeptide substrates, allosteric regulation in the course of preprotein translocation. Import of radio-labeled preprotein b2-DHFR fusion protein Saccharomyces cerevisiae ADP + phosphate
-
?
additional information even a partial disruption of the interdomain communication in the mtHsp70 chaperone results in an almost complete breakdown of its translocation-driving properties Saccharomyces cerevisiae ?
-
?
additional information interaction of mtHsp70 with partner proteins Mdj1, Mge1, and Tim44 Saccharomyces cerevisiae ?
-
?

Synonyms

Synonyms Comment Organism
Hsp70
-
Saccharomyces cerevisiae
More the enzyme belongs to the chaperones of the 70-kDa family, Hsp70 Saccharomyces cerevisiae

Temperature Optimum [°C]

Temperature Optimum [°C] Temperature Optimum Maximum [°C] Comment Organism
25
-
assay at Saccharomyces cerevisiae

pH Optimum

pH Optimum Minimum pH Optimum Maximum Comment Organism
7.4
-
assay at Saccharomyces cerevisiae

Cofactor

Cofactor Comment Organism Structure
ATP
-
Saccharomyces cerevisiae