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[
Proteins,
2003]
Triosephosphate isomerase (TIM, E.C. 5.3.1.1) catalyzes the reversible isomerization of dihydroxyacetone phosphate to D-glyceraldehyde 3-phosphate in the glycolytic pathway. It is a well-studied enzyme conserved in function across eukarya, bacteria, and archaea.
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[
Proteins,
2003]
The biosynthesis of catecholamnes includes hydroxylation of the aromatic amino acids phenylalanin, tyrosine, and tryptophan. Corresponding hydroxylases use tetrahydrobiopterin (BH4), which is oxidized to a quinonoid form of dihydrobiopterin.
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[
Proteins,
2003]
Calmodulin (CaM), a conserved eucaryotic protein, can bind specifically to a large number of intracellular proteins and modulate their activity in response to the Ca2+ concentration. This small 17-kDa acidic protein belongs to a family of homologous calcium-binding proteins that bind Ca2+ through the EF-hand motif (e.g., parvalbumin or troponin C). A compact, calcium-free, apo form of CaM is converted to an extended dumbbell-shaped form on binding Ca2+.
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[
Acta Crystallogr D Biol Crystallogr,
2004]
Binding of the BAG domain to the eukaryotic chaperone heat-shock protein (Hsp70) promotes ATP-dependent release of the protein substrate from Hsp70. Although the murine and human BAG domains have been shown to form an antiparallel three-helix bundle, the Caenorhabditis elegans BAG domain is formed by two antiparallel helices, while the third helix is extended away and stabilized by crystal-packing interactions. A small beta-sheet between helices 2 and 3 interferes with formation of the intramolecular three-helix bundle. However, intermolecular three-helix bundles are observed throughout the crystal packing and suggest that stable functional dimers and tetramers can be formed in solution. The structure may represent a new folding type of the BAG domain.
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[
Biochemistry,
1987]
The major intestinal esterase from the nematode Caenorhabditis elegans has been purified to essential homogeneity. Starting from whole worms, the overall purification is 9000-fold with a 10% recovery of activity. The esterase is a single polypeptide chain of Mr 60,000 and is stoichiometrically inhibited by organophosphates. Substrate preferences and inhibition patterns classify the enzyme as a carboxylesterase (EC 3.1.1.1), but the physiological function is unknown. The sequence of 13 amino acid residues at the esterase N- terminus has been determined. This partial sequence shows a surprisingly high degree of similarity to the N-terminal sequence of two carboxylesterases recently isolated from Drosophila mojavensis [Pen, J., van Beeumen, J., & Beintema, J. J. (1986) Biochem. J. 238, 691-699].
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[
Acta Crystallogr D Biol Crystallogr,
2004]
Structural data are reported for SSP-19, a sperm-specific protein (SSP) family member from Caenorhabditis elegans. The SSP family [also known as the major sperm protein-like (MSP-like) family] contains proteins with only 107-109 amino acids, compared with 127 amino acids in the major sperm protein (MSP) family. MSP, the most abundant protein in nematode sperm, forms a dynamic actin-like cytoskeleton that provides the framework for the nematode sperm motility. In vivo, MSP dimers polymerize to form filaments that are constructed from two helical strands, which assemble into larger macromolecular structures. Little is known about the SSP family and a similar function is inferred from sequence and structural homology [Pfam (Protein Families Database of Alignments and HMMs) and SCOP (Structural Classification of Proteins) classification]. Despite the overall structural homology, the monomer-monomer interactions in SSP-19 are strikingly different from the interactions in the two MSP canonic domains described previously.
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[
Curr Biol,
1999]
In this Brief Communication, which appeared in the 14 September 1998 issue of Current Biology, the UV dose was reported erroneously. The dose reported was 20 J/m2 but the actual dose used was 0.4 J/cm2. Also, the gene formally referred to as
tkr-1 has since been renamed
old-1 (overexpression longevity determination).
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[
J Bacteriol,
2014]
Volume 195, no. 16, p. 35143523, 2013. A number of problems related to images published in this paper have been brought to our attention. Figure 1D contains duplicated images in lanes S and LE, and Fig. 4D and 6B contain images previously published in articles in this journal and in Microbiology and Microbial Pathogenesis, i.e., the following: C. G. Ramos, S. A. Sousa, A. M. Grilo, J. R. Feliciano, and J. H. Leitao, J. Bacteriol. 193:15151526, 2011. doi:10.1128/JB.01374-11. S. A. Sousa, C. G. Ramos, L. M. Moreira, and J. H. Leitao, Microbiology 156:896908, 2010. doi:10.1099/mic.0.035139-0. C. G. Ramos, S. A. Sousa, A. M. Grilo, L. Eberl, and J. H. Leitao, Microb. Pathog. 48:168177, 2010. doi: 10.1016/j.micpath.2010.02.006. Therefore, we retract the paper. We deeply regret this situation and apologize for any inconvenience to the editors and readers of Journal of Bacteriology, Microbial Pathogenesis, and Microbiology.
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Berynskyy M, Morimoto RI, Bukau B, Stengel F, Kirstein J, Szlachcic A, Arnsburg K, Stank A, Scior A, Nillegoda NB, Gao X, Guilbride DL, Aebersold R, Wade RC, Mayer MP
[
Nature,
2015]
Protein aggregates are the hallmark of stressed and ageing cells, and characterize several pathophysiological states. Healthy metazoan cells effectively eliminate intracellular protein aggregates, indicating that efficient disaggregation and/or degradation mechanisms exist. However, metazoans lack the key heat-shock protein disaggregase HSP100 of non-metazoan HSP70-dependent protein disaggregation systems, and the human HSP70 system alone, even with the crucial HSP110 nucleotide exchange factor, has poor disaggregation activity in vitro. This unresolved conundrum is central to protein quality control biology. Here we show that synergic cooperation between complexed J-protein co-chaperones of classes A and B unleashes highly efficient protein disaggregation activity in human and nematode HSP70 systems. Metazoan mixed-class J-protein complexes are transient, involve complementary charged regions conserved in the J-domains and carboxy-terminal domains of each J-protein class, and are flexible with respect to subunit composition. Complex formation allows J-proteins to initiate transient higher order chaperone structures involving HSP70 and interacting nucleotide exchange factors. A network of cooperative class A and B J-protein interactions therefore provides the metazoan HSP70 machinery with powerful, flexible, and finely regulatable disaggregase activity and a further level of regulation crucial for cellular protein quality control.
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[
Worm Breeder's Gazette,
1992]
unc-4 LacZ expression in A-type motor neurons David M. Miller and Charles J. Niemeyer, Dept. of Cell Biology, Duke Univ. Medical Ctr, Durham, NC 27710