scholarly journals Yeast acyl-CoA-binding protein: acyl-CoA-binding affinity and effect on intracellular acyl-CoA pool size

1994 ◽  
Vol 302 (2) ◽  
pp. 479-485 ◽  
Author(s):  
J Knudsen ◽  
N J Faergeman ◽  
H Skøtt ◽  
R Hummel ◽  
C Børsting ◽  
...  

Acyl-CoA-binding protein (ACBP) is a 10 kDa protein characterized in vertebrates. We have isolated two ACBP homologues from the yeast Saccharomyces carlsbergensis, named yeast ACBP types 1 and 2. Both proteins contain 86 amino acid residues and are identical except for four conservative substitutions. In comparison with human ACBP, yeast ACBPs exhibit 48% (type 1) and 49% (type 2) conservation of amino acid residues. The amino acid sequence of S. carlsbergensis ACBP type 1 was found to be identical with the one ACBP present in Saccharomyces cerevisiae. A recombinant form of this protein was expressed in Escherichia coli and S. cerevisiae, purified, and its acyl-CoA-binding properties were characterized by isoelectric focusing and microcalorimetric analyses. The yeast ACBP was found to bind acyl-CoA esters with high affinity (Kd 0.55 x 10(-10) M). Overexpression of yeast ACBP in S. cerevisiae resulted in a significant expansion of the intracellular acyl-CoA pool. Finally, Southern-blotting analysis of the two genes encoding ACBP types 1 and 2 in S. carlsbergensis strongly indicated that this species is a hybrid between S. cerevisiae and Saccharomyces monacensis.

2005 ◽  
Vol 26 (3) ◽  
pp. 117-121 ◽  
Author(s):  
Saori TAKAHASHI ◽  
Hironobu OGASAWARA ◽  
Kazuyuki HIWATASHI ◽  
Keishi HATA ◽  
Kazuyuki HORI ◽  
...  

2015 ◽  
Vol 81 (21) ◽  
pp. 7553-7559 ◽  
Author(s):  
Nidhi Shrivastava ◽  
Zbynek Prokop ◽  
Ashwani Kumar

ABSTRACTLinA is the first enzyme of the microbial degradation pathway of a chlorinated insecticide, hexachlorocyclohexane (HCH), and mediates the dehydrochlorination of α-, γ-, and δ-HCH. Its two variants, LinA type 1 and LinA type 2, which differ at 10 out of 156 amino acid residues, have been described. Their activities for the metabolism of different HCH isomers differ considerably but overall are high for γ-HCH, moderate for α-HCH, low for δ-HCH, and lacking for β-HCH. Here, we describe the characterization of a new variant of this enzyme, LinA type 3, whose gene was identified from the metagenome of an HCH-contaminated soil sample. Its deduced primary structure in the region spanning amino acid residues 1 to 147 of the protein exhibits 17 and 12 differences from LinA type 1 and LinA type 2, respectively. In addition, the residues GIHFAPS, present at the region spanning residues 148 to 154 in both LinA type 1 and LinA type 2, are deleted in LinA type 3.The activity of LinA type 3 for the metabolism of δ-HCH is several orders of magnitude higher than that of LinA type 1 or LinA type 2 and can be useful for improvement of the metabolism of δ-HCH.


1998 ◽  
Vol 18 (9) ◽  
pp. 5052-5061 ◽  
Author(s):  
Robert Harrod ◽  
Yong Tang ◽  
Christophe Nicot ◽  
Hsieng S. Lu ◽  
Alex Vassilev ◽  
...  

ABSTRACT Human T-cell lymphotropic virus type 1 (HTLV-1) transcriptional activation is mediated by the viral transactivator, Tax, and three 21-bp repeats (Tax response element [TxRE]) located in the U3 region of the viral long terminal repeat (LTR). Each TxRE contains a core cyclic AMP response element (CRE) flanked by 5′ G-rich and 3′ C-rich sequences. The TxRE binds CREB (CRE-binding protein) and Tax to form a ternary complex and confers Tax-dependent transactivation. Recent data indicate that Tax functions as a specific link to connect CREB-binding protein (CBP)/p300 in a phosphorylation-independent manner to CREB/ATF-1 assembled on the viral 21-bp repeats. GlutathioneS-transferase pull-down performed with Tax deletion mutants and peptide competition have localized the site in Tax critical for binding CBP/p300 to a highly protease-sensitive region around amino acid residues 81 to 95 (81QRTSKTLKVLTPPIT95) which lies between the domains previously proposed to be important for CREB binding and Tax subunit dimerization. Amino acid residues around the trypsin- and chymotrypsin-sensitive sites (88KVL90) of Tax bear resemblance to those in the kinase-inducible domain of CREB (129SRRPSYRKILNE140) surrounding Ser-133, which undergoes signal-induced phosphorylation to recruit CBP/p300. Site-directed mutagenesis of residues in this domain (R82A, K85A, K88A, and V89A) resulted in proteins which failed to transactivate from the HTLV-1 LTR in vivo. These mutants (K85A, K88A, and V89A) bind CREB with similar affinities as wild-type Tax, yet interaction with CBP/p300 is abrogated in various biochemical assays, indicating that the recruitment of CBP/p300 is crucial for Tax transactivation. A Tax mutant, M47, defective in the COOH-terminal transactivation domain, continued to interact with CBP/p300, suggesting that interactions with additional cellular factors are required for proper Tax function.


1998 ◽  
Vol 66 (4) ◽  
pp. 1482-1491 ◽  
Author(s):  
Maria K. Yeung ◽  
Jacob A. Donkersloot ◽  
John O. Cisar ◽  
Pamela A. Ragsdale

ABSTRACT The nucleotide sequence of the Actinomyces naeslundiiT14V type 2 fimbrial structural subunit gene, fimA, and the 3′ flanking DNA region was determined. The fimA gene encoded a 535-amino-acid precursor subunit protein (FimA) which included both N-terminal leader and C-terminal cell wall sorting sequences. A second gene, designated orf365, that encoded a 365-amino-acid protein which contained a putative transmembrane segment was identified immediately 3′ to fimA. Mutants in which either fimA or orf365 was replaced with a kanamycin resistance gene did not participate in type 2 fimbriae-mediated coaggregation with Streptococcus oralis34. Type 2 fimbrial antigen was not detected in cell extracts of thefimA mutant by Western blotting with anti-A. naeslundii type 2 fimbrial antibody, but the subunit protein was detected in extracts of the orf365 mutant. The subunit protein detected in this mutant also was immunostained by an antibody raised against a synthetic peptide representing the C-terminal 20 amino acid residues of the predicted FimA. The antipeptide antibody reacted with FimA isolated from the recombinant Escherichia coliclone containing fimA but did not react with purified type 2 fimbriae in extracts of the wild-type strain. These results indicate that synthesis of type 2 fimbriae in A. naeslundii T14V may involve posttranslational cleavage of both the N-terminal and C-terminal peptides of the precursor subunit and also the expression oforf365.


2021 ◽  
Vol 22 (16) ◽  
pp. 8964
Author(s):  
Sara Ragucci ◽  
Daniela Bulgari ◽  
Nicola Landi ◽  
Rosita Russo ◽  
Angela Clemente ◽  
...  

Quinoin is a type 1 ribosome-inactivating protein (RIP) we previously isolated from the seeds of pseudocereal quinoa (Chenopodium quinoa) and is known as a functional food for its beneficial effects on human health. As the presence of RIPs in edible plants could be potentially risky, here we further characterised biochemically the protein (complete amino acid sequence, homologies/differences with other RIPs and three-dimensional homology modeling) and explored its possible defensive role against pathogens. Quinoin consists of 254 amino acid residues, without cysteinyl residues. As demonstrated by similarities and homology modeling, quinoin preserves the amino acid residues of the active site (Tyr75, Tyr122, Glu177, Arg180, Phe181 and Trp206; quinoin numbering) and the RIP-fold characteristic of RIPs. The polypeptide chain of quinoin contains two N-glycosylation sites at Asn115 and Asp231, the second of which appears to be linked to sugars. Moreover, by comparative MALDI-TOF tryptic peptide mapping, two differently glycosylated forms of quinoin, named pre-quinoin-1 and pre-quinoin-2 (~0.11 mg/100 g and ~0.85 mg/100 g of seeds, respectively) were characterised. Finally, quinoin possesses: (i) strong antiviral activity, both in vitro and in vivo towards Tobacco Necrosis Virus (TNV); (ii) a growth inhibition effect on the bacterial pathogens of plants; and (iii) a slight antifungal effect against two Cryphonectria parasitica strains.


2006 ◽  
Vol 281 (30) ◽  
pp. 21022-21031 ◽  
Author(s):  
James D. Fessenden ◽  
Wei Feng ◽  
Isaac N. Pessah ◽  
Paul D. Allen

1983 ◽  
Vol 211 (1) ◽  
pp. 109-118 ◽  
Author(s):  
H Ohtake ◽  
T Suyemitsu ◽  
M Koga

Gel-filtration analysis of cytosol fraction obtained from unfertilized sea-urchin (Anthocidaris crassispina) eggs on Sephadex G-75 revealed the presence of two Zn-binding-protein fractions. The major Zn-binding protein fraction had a low molecular weight and a low absorbance at 280 nm, properties similar to those of the metallothionein found in the regenerating rat liver. These fractions were further purified by DEAE-cellulose and Sephadex G-50 chromatography. Homogeneity of the Zn-binding protein was judged by polyacrylamide-disc-gel electrophoresis and gel-permeation chromatography in the presence of 6 M-guanidinium chloride. The molecular weight determined by gel-permeation chromatography was 3900. This value is in good agreement with the minimum molecular weight calculated from the amino acid composition, which was 3655. Zn-binding protein is composed of 36 amino acid residues and the distinctive features include an extremely high content of cysteine, which accounted for one-third of the total amino acid residues, and a complete absence of aromatic amino acids, as well as of methionine, histidine and arginine. Zn-binding protein contained 4.1 g-atoms of zinc per mol and a trace of cadmium, but no copper, iron or calcium. The molar ratio of reactive thiol groups to metal ion was calculated to be 2.73:1. Possible roles of this Zn-binding protein in the homoeostasis of zinc in unfertilized sea-urchin eggs are discussed.


1998 ◽  
Vol 273 (26) ◽  
pp. 15927-15932 ◽  
Author(s):  
Eduardo Sainz ◽  
Mark Akeson ◽  
Samuel A. Mantey ◽  
Robert T. Jensen ◽  
James F. Battey

2006 ◽  
Vol 50 (11) ◽  
pp. 3638-3645 ◽  
Author(s):  
Sho Takahata ◽  
Nami Senju ◽  
Yumi Osaki ◽  
Takuji Yoshida ◽  
Takashi Ida

ABSTRACT The molecular mechanisms of reduced susceptibility to cefixime in clinical isolates of Neisseria gonorrhoeae, particularly amino acid substitutions in mosaic penicillin-binding protein 2 (PBP2), were examined. The complete sequence of ponA, penA, and por genes, encoding, respectively, PBP1, PBP2, and porin, were determined for 58 strains isolated in 2002 from Japan. Replacement of leucine 421 by proline in PBP1 and the mosaic-like structure of PBP2 were detected in 48 strains (82.8%) and 28 strains (48.3%), respectively. The presence of mosaic PBP2 was the main cause of the elevated cefixime MIC (4- to 64-fold). In order to identify the mutations responsible for the reduced susceptibility to cefixime in isolates with mosaic PBP2, penA genes with various mutations were transferred to a susceptible strain by genetic transformation. The susceptibility of partial recombinants and site-directed mutants revealed that the replacement of glycine 545 by serine (G545S) was the primary mutation, which led to a two- to fourfold increase in resistance to cephems. Replacement of isoleucine 312 by methionine (I312M) and valine 316 by threonine (V316T), in the presence of the G545S mutation, reduced susceptibility to cefixime, ceftibuten, and cefpodoxime by an additional fourfold. Therefore, three mutations (G545S, I312M, and V316T) in mosaic PBP2 were identified as the amino acid substitutions responsible for reduced susceptibility to cefixime in N. gonorrhoeae.


Sign in / Sign up

Export Citation Format

Share Document