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Nature Communications 2014Reversible protein phosphorylation is the most widespread regulatory mechanism in signal transduction. Autophosphorylation in a dimeric sensor histidine kinase is the...
Reversible protein phosphorylation is the most widespread regulatory mechanism in signal transduction. Autophosphorylation in a dimeric sensor histidine kinase is the first step in two-component signalling, the predominant signal-transduction device in bacteria. Despite being the most abundant sensor kinases in nature, the molecular bases of the histidine kinase autophosphorylation mechanism are still unknown. Furthermore, it has been demonstrated that autophosphorylation can occur in two directions, cis (intrasubunit) or trans (intersubunit) within the dimeric histidine kinase. Here, we present the crystal structure of the complete catalytic machinery of a chimeric histidine kinase. The structure shows an asymmetric histidine kinase dimer where one subunit is caught performing the autophosphorylation reaction. A structure-guided functional analysis on HK853 and EnvZ, two prototypical cis- and trans-phosphorylating histidine kinases, has allowed us to decipher the catalytic mechanism of histidine kinase autophosphorylation, which seems to be common independently of the reaction directionality.
Topics: Amino Acid Sequence; Bacterial Outer Membrane Proteins; Catalytic Domain; DNA Mutational Analysis; Escherichia coli Proteins; Histidine Kinase; Molecular Sequence Data; Multienzyme Complexes; Phosphorylation; Protein Conformation; Protein Kinases; Structure-Activity Relationship
PubMed: 24500224
DOI: 10.1038/ncomms4258 -
Applied and Environmental Microbiology Feb 2005
Review
Topics: Alcaligenes; Amino Acid Sequence; Arsenic; Arsenite Transporting ATPases; Bacterial Proteins; Inorganic Chemicals; Ion Pumps; Molecular Sequence Data; Multienzyme Complexes; Oxidation-Reduction; Oxidoreductases
PubMed: 15691908
DOI: 10.1128/AEM.71.2.599-608.2005 -
Structure (London, England : 1993) May 1995The structure of the proteasome from Thermoplasma acidophilum introduces threonine proteases as a fifth class of proteolytic enzymes, and offers insights into the... (Review)
Review
The structure of the proteasome from Thermoplasma acidophilum introduces threonine proteases as a fifth class of proteolytic enzymes, and offers insights into the catalytic activity of this complicated piece of molecular machinery with its 14 active sites.
Topics: Amino Acid Sequence; Bacterial Proteins; Binding Sites; Crystallography, X-Ray; Cysteine Endopeptidases; Microscopy, Electron; Models, Molecular; Molecular Sequence Data; Multienzyme Complexes; Proteasome Endopeptidase Complex; Protein Conformation; Thermoplasma
PubMed: 7663937
DOI: 10.1016/S0969-2126(01)00172-1 -
Cell Nov 1997
Review
Topics: Adenosine Triphosphate; Carrier Proteins; Cysteine Endopeptidases; Endopeptidases; Models, Molecular; Multienzyme Complexes; Proteasome Endopeptidase Complex
PubMed: 9390550
DOI: 10.1016/s0092-8674(00)80427-4 -
Journal of Neurochemistry Oct 2002Filamentous inclusions composed of the microtubule-associated protein tau are a defining characteristic of a large number of neurodegenerative diseases. Here we show...
Filamentous inclusions composed of the microtubule-associated protein tau are a defining characteristic of a large number of neurodegenerative diseases. Here we show that tau degradation in stably transfected and non-transfected SH-SY5Y cells is blocked by the irreversible proteasome inhibitor lactacystin. Further, we find that in vitro, natively unfolded tau can be directly processed by the 20S proteasome without a requirement for ubiquitylation, and that a highly reproducible pattern of degradation intermediates is readily detectable during this process. Analysis of these intermediates shows that 20S proteasomal processing of tau is bi-directional, proceeding from both N- and C-termini, and that populations of relatively stable intermediates arise probably because of less efficient digestion of the C-terminal repeat region. Our results are consistent with an in vivo role for the proteasome in tau degradation and support the existence of ubiquitin-independent pathways for the proteasomal degradation of unfolded proteins.
Topics: Acetylcysteine; Blotting, Western; Cysteine Endopeptidases; Cysteine Proteinase Inhibitors; Humans; Multienzyme Complexes; Neuroblastoma; Proteasome Endopeptidase Complex; Protein Folding; Protein Isoforms; Transfection; Tumor Cells, Cultured; Ubiquitin; tau Proteins
PubMed: 12358741
DOI: 10.1046/j.1471-4159.2002.01137.x -
Cell May 2000
Review
Topics: Animals; Cysteine Endopeptidases; Humans; Multienzyme Complexes; Ornithine Decarboxylase; Proteasome Endopeptidase Complex; Signal Transduction; Ubiquitins
PubMed: 10830160
DOI: 10.1016/s0092-8674(00)80843-0 -
FEBS Letters Aug 2001The structure of Wolinella succinogenes quinol:fumarate reductase by X-ray crystallography has been determined at 2.2-A resolution [Lancaster et al. (1999), Nature 402,... (Review)
Review
The structure of Wolinella succinogenes quinol:fumarate reductase by X-ray crystallography has been determined at 2.2-A resolution [Lancaster et al. (1999), Nature 402, 377-385]. Based on the structure of the three protein subunits A, B, and C and the arrangement of the six prosthetic groups (a covalently bound FAD, three iron-sulphur clusters, and two haem b groups) a pathway of electron transfer from the quinol-oxidising dihaem cytochrome b in the membrane to the site of fumarate reduction in the hydrophilic subunit A has been proposed. By combining the results from site-directed mutagenesis, functional and electrochemical characterisation, and X-ray crystallography, a residue was identified which is essential for menaquinol oxidation. [Lancaster et al. (2000), Proc. Natl. Acad. Sci. USA 97, 13051-13056]. The location of this residue in the structure suggests that the coupling of the oxidation of menaquinol to the reduction of fumarate in dihaem-containing succinate:quinone oxidoreductases could be associated with the generation of a transmembrane electrochemical potential. Based on crystallographic analysis of three different crystal forms of the enzyme and the results from site-directed mutagenesis, we have derived a mechanism of fumarate reduction and succinate oxidation [Lancaster et al. (2001) Eur. J. Biochem. 268, 1820-1827], which should be generally relevant throughout the superfamily of succinate:quinone oxidoreductases.
Topics: Cell Membrane; Crystallography, X-Ray; Electron Transport; Electron Transport Complex II; Models, Biological; Models, Chemical; Models, Molecular; Multienzyme Complexes; Mutagenesis, Site-Directed; Oxidoreductases; Oxygen; Protein Conformation; Protons; Succinate Dehydrogenase; Wolinella
PubMed: 11532445
DOI: 10.1016/s0014-5793(01)02706-5 -
Journal of Bacteriology Oct 1983The oxidative decarboxylations of pyruvate and 2-oxoglutarate in Escherichia coli are carried out by two large, multienzyme complexes: pyruvate dehydrogenase and...
The oxidative decarboxylations of pyruvate and 2-oxoglutarate in Escherichia coli are carried out by two large, multienzyme complexes: pyruvate dehydrogenase and 2-oxoglutarate dehydrogenase. The enzyme complexes each contain three subunits: two are unique to the individual complexes, the third is shared between them. Resolution of the polypeptide subunits on two-dimensional gels allowed quantitative analysis of their cellular levels and patterns of synthesis in growing cells. Cells growing in glucose-salts medium were found to contain roughly 85 to 136 pyruvate dehydrogenase complexes and 73 2-oxoglutarate complexes. Lipoamide dehydrogenase, the subunit shared by the two complexes, was found to be in significant excess of its stoichiometric demand in the two enzyme complexes under most growth conditions. The subunits unique to each of the complexes were coordinately regulated over a wide variety of growth conditions and a broad range of expression. The two complexes responded to different, but partially overlapping, regulatory signals. Most importantly, the shared subunit was actively regulated to accommodate its demand in both enzymes. These results are discussed with regard to possible mechanisms of regulation of the enzyme complexes in general and of the shared subunit specifically.
Topics: 3-Methyl-2-Oxobutanoate Dehydrogenase (Lipoamide); Culture Media; DNA Transposable Elements; Dihydrolipoamide Dehydrogenase; Escherichia coli; Ketone Oxidoreductases; Multienzyme Complexes; Mutation; Pyruvate Dehydrogenase Complex
PubMed: 6311808
DOI: 10.1128/jb.156.1.81-88.1983 -
Cell Sep 1995
Review
Topics: Cysteine Endopeptidases; Multienzyme Complexes; Proteasome Endopeptidase Complex; Proteins
PubMed: 7553848
DOI: 10.1016/0092-8674(95)90021-7 -
The Journal of Biological Chemistry Aug 1999
Review
Topics: Cysteine Endopeptidases; Gene Expression Regulation, Enzymologic; Models, Biological; Multienzyme Complexes; Proteasome Endopeptidase Complex; Proteins; Ubiquitins
PubMed: 10428771
DOI: 10.1074/jbc.274.32.22123