scholarly journals Discovery of a new ATP-binding motif involved in peptidic azoline biosynthesis

2014 ◽  
Vol 10 (10) ◽  
pp. 823-829 ◽  
Author(s):  
Kyle L Dunbar ◽  
Jonathan R Chekan ◽  
Courtney L Cox ◽  
Brandon J Burkhart ◽  
Satish K Nair ◽  
...  
Keyword(s):  
Atp Binding ◽  
Binding Motif

scholarly journals Anabaena sp. Strain PCC 7120 hetY Gene Influences Heterocyst Development

2003 ◽  
Vol 185 (23) ◽  
pp. 6995-7000 ◽  
Author(s):  
Ho-Sung Yoon ◽  
Martin H. Lee ◽  
Jin Xiong ◽  
James W. Golden
Keyword(s):  
Atp Binding ◽  
Binding Motif ◽  
Filamentous Cyanobacterium ◽  
Hypothetical Proteins ◽  
Nitrogen Fixing ◽  
Fixed Nitrogen ◽  
Anabaena Sp ◽  
Time Required ◽  
Pcc 7120 ◽  
Heterocyst Development

ABSTRACT The filamentous cyanobacterium Anabaena (Nostoc) sp. strain PCC 7120 responds to starvation for fixed nitrogen by producing a semiregular pattern of nitrogen-fixing cells called heterocysts. Overexpression of the hetY gene partially suppressed heterocyst formation, resulting in an abnormal heterocyst pattern. Inactivation of hetY increased the time required for heterocyst maturation and caused defects in heterocyst morphology. The 489-bp hetY gene (alr2300), which is adjacent to patS (asl2301), encodes a protein that belongs to a conserved family of bacterial hypothetical proteins that contain an ATP-binding motif.

scholarly journals Characterization of the ATP-hydrolysing activity of α-sarcoglycan

2004 ◽  
Vol 381 (1) ◽  
pp. 105-112 ◽  
Author(s):  
Dorianna SANDONÀ ◽  
Stefano GASTALDELLO ◽  
Tiziana MARTINELLO ◽  
Romeo BETTO
Keyword(s):  
Muscular Dystrophy ◽  
Molecular Mechanisms ◽  
C2c12 Cells ◽  
C2c12 Myotubes ◽  
Atp Binding ◽  
Binding Motif ◽  
Nucleotidase Activity ◽  
Reactive Blue 2 ◽  
Definitive Evidence ◽  
Dystrophin Complex

α-Sarcoglycan is a glycoprotein associated with the dystrophin complex at sarcolemma of skeletal and cardiac muscles. Gene defects in α-sarcoglycan lead to a severe muscular dystrophy whose molecular mechanisms are not yet clear. A first insight into the function of α-sarcoglycan was obtained by finding that it is an ATP-binding protein and that it probably confers ability to hydrolyse ATP to the purified dystrophin complex [Betto, Senter, Ceoldo, Tarricone, Biral and Salviati (1999) J. Biol. Chem. 274, 7907–7912]. In the present study, we present definitive evidence showing that α-sarcoglycan is an ATP-hydrolysing enzyme. The appearance of α-sarcoglycan protein expression was correlated with the increase in ecto-nucleotidase activity during differentiation of C2C12 cells. Approx. 25% of ecto-nucleotidase activity displayed by the C2C12 myotubes was inhibited by preincubating cells with an antibody specific for the ATP-binding motif of α-sarcoglycan. This demonstrates that α-sarcoglycan substantially contributes to total ecto-nucleotidase activity of C2C12 myotubes. To characterize further this activity, human embryonic kidney 293 cells were transfected with expression plasmids containing α-sarcoglycan cDNA. Transfected cells exhibited a significant increase in the ATP-hydrolysing activity that was abolished by the anti-α-sarcoglycan antibody. The enzyme had a substrate specificity for ATP and ADP, did not hydrolyse other triphosphonucleosides, and the affinity for ATP was in the low mM range. The ATPase activity strictly required the presence of both Mg2+ and Ca2+ and was completely inhibited by suramin and reactive blue-2. These results show that α-sarcoglycan is a Ca2+, Mg2+-ecto-ATPDase. The possible consequences of the absence of α-sarcoglycan activity in the pathogenesis of muscular dystrophy are discussed.

scholarly journals Interactions of ATP, oestradiol, genistein and the anti-oestrogens, faslodex (ICI 182780) and tamoxifen, with the human erythrocyte glucose transporter, GLUT1

2002 ◽  
Vol 365 (3) ◽  
pp. 707-719 ◽  
Author(s):  
Iram AFZAL ◽  
Philip CUNNINGHAM ◽  
Richard. J. NAFTALIN
Keyword(s):  
Binding Site ◽  
Oestrogen Receptor ◽  
Glucose Transporter ◽  
Three Dimensional ◽  
Inhibitory Effect ◽  
Atp Binding ◽  
Binding Motif ◽  
Transmembrane Helices ◽  
Selective Oestrogen Receptor Modulators ◽  
Dependent Inhibition

17β-Oestradiol (ED when subscript to K) and the phytoestrogen isoflavone genistein (GEN) inhibit glucose transport in human erythrocytes and erythrocyte ghosts. The selective oestrogen receptor modulators or anti-oestrogens, faslodex (ICI 182780) (FAS) and tamoxifen (TAM), competitively antagonize oestradiol inhibition of glucose exit from erythrocytes (Ki(ED/FAS) = 2.84±0.16μM and Ki(ED/TAM) = 100±2nM). Faslodex has no significant inhibitory effect on glucose exit, but tamoxifen alone inhibits glucose exit (Ki(TAM) = 300±100nM). In ghosts, ATP (1–4mM) competitively antagonizes oestradiol, genistein and cytochalasin B (CB)-dependent inhibitions of glucose exit, (Ki(ATP/ED) = 2.5±0.23mM, Ki(ATP/GEN) = 0.99±0.17mM and Ki(ATP/CB) = 0.76±0.08mM). Tamoxifen and faslodex reverse oestradiol-dependent inhibition of glucose exit with ATP>1mM (Ki(ED/TAM) = 130±5nM and Ki(ED/FAS) = 2.7±0.9μM). The cytoplasmic surface of the glucose transporter (GLUT)1 contains four sequences with close homologies to sequences in the ligand-binding domain of human oestrogen receptor β (hesr-2). One homology is adjacent to the Walker ATP-binding motif II (GLUT1, residues 225–229) in the large cytoplasmic segment linking transmembrane helices 6 and 7; another GLUT (residues 421–423) contains the Walker ATP-binding motif III. Mapping of these regions on to a three-dimensional template of GLUT indicates that a possible oestrogen-binding site lies between His337, Arg349 and Glu249 at the cytoplasmic entrance to the hydrophilic pore spanning GLUT, which have a similar topology to His475, Glu305 and Arg346 in hesr-2 that anchor the head and tail hydroxy groups of oestradiol and genistein, and thus are suitably placed to provide an ATP-sensitive oestrogen binding site that could modulate glucose export.

scholarly journals Molecular interaction of nitrate transporter proteins with recombinant glycinebetaine results in efficient nitrate uptake in the cyanobacterium Anabaena PCC 7120

PLoS ONE ◽  
2021 ◽  
Vol 16 (11) ◽  
pp. e0257870
Author(s):  
Prashant Swapnil ◽  
Mukesh Meena ◽  
Ashwani K. Rai
Keyword(s):  
Amino Acids ◽  
Abc Transporter ◽  
Molecular Interaction ◽  
Transmembrane Domain ◽  
Binding Domain ◽  
Nitrate Transport ◽  
Atp Binding ◽  
Binding Motif ◽  
Transporter Proteins ◽  
Pcc 7120

Nitrate transport in cyanobacteria is mediated by ABC-transporter, which consists of a highly conserved ATP binding cassette (ABC) and a less conserved transmembrane domain (TMD). Under salt stress, recombinant glycinebetaine (GB) not only protected the rate of nitrate transport in transgenic Anabaena PCC 7120, rather stimulated the rate by interacting with the ABC-transporter proteins. In silico analyses revealed that nrtA protein consisted of 427 amino acids, the majority of which were hydrophobic and contained a Tat (twin-arginine translocation) signal profile of 34 amino acids (1–34). The nrtC subunit of 657 amino acids contained two hydrophobic distinct domains; the N-terminal (5–228 amino acids), which was 59% identical to nrtD (the ATP-binding subunit) and the C-terminal (268–591), 28.2% identical to nrtA, suggesting C-terminal as a solute binding domain and N-terminal as ATP binding domain. Subunit nrtD consisted of 277 amino acids and its N-terminal (21–254) was an ATP binding motif. Phylogenetic analysis revealed that nitrate-ABC-transporter proteins are highly conserved among the cyanobacterial species, though variation existed in sequences resulting in several subclades. Nostoc PCC 7120 was very close to Anabaena variabilis ATCC 29413, Anabaena sp. 4–3 and Anabaena sp. CA = ATCC 33047. On the other, Nostoc spp. NIES-3756 and PCC 7524 were often found in the same subclade suggesting more work before referring it to Anabaena PCC 7120 or Nostoc PCC 7120. The molecular interaction of nitrate with nrtA was hydrophilic, while hydrophobic with nrtC and nrtD. GB interaction with nrtACD was hydrophobic and showed higher affinity compared to nitrate.

scholarly journals Bioinformatics Investigations of Universal Stress Proteins from Mercury-Methylating Desulfovibrionaceae

2021 ◽  
Vol 9 (8) ◽  
pp. 1780
Author(s):  
Raphael D. Isokpehi ◽  
Dominique S. McInnis ◽  
Antoinette M. Destefano ◽  
Gabrielle S. Johnson ◽  
Akimio D. Walker ◽  
...  
Keyword(s):  
Visual Analytics ◽  
Stress Proteins ◽  
Stress Protein ◽  
Inorganic Mercury ◽  
Food Sources ◽  
Aquatic Environments ◽  
Atp Binding ◽  
Binding Motif ◽  
Universal Stress Protein ◽  
Methylmercury Production

The presence of methylmercury in aquatic environments and marine food sources is of global concern. The chemical reaction for the addition of a methyl group to inorganic mercury occurs in diverse bacterial taxonomic groups including the Gram-negative, sulfate-reducing Desulfovibrionaceae family that inhabit extreme aquatic environments. The availability of whole-genome sequence datasets for members of the Desulfovibrionaceae presents opportunities to understand the microbial mechanisms that contribute to methylmercury production in extreme aquatic environments. We have applied bioinformatics resources and developed visual analytics resources to categorize a collection of 719 putative universal stress protein (USP) sequences predicted from 93 genomes of Desulfovibrionaceae. We have focused our bioinformatics investigations on protein sequence analytics by developing interactive visualizations to categorize Desulfovibrionaceae universal stress proteins by protein domain composition and functionally important amino acids. We identified 651 Desulfovibrionaceae universal stress protein sequences, of which 488 sequences had only one USP domain and 163 had two USP domains. The 488 single USP domain sequences were further categorized into 340 sequences with ATP-binding motif and 148 sequences without ATP-binding motif. The 163 double USP domain sequences were categorized into (1) both USP domains with ATP-binding motif (3 sequences); (2) both USP domains without ATP-binding motif (138 sequences); and (3) one USP domain with ATP-binding motif (21 sequences). We developed visual analytics resources to facilitate the investigation of these categories of datasets in the presence or absence of the mercury-methylating gene pair (hgcAB). Future research could utilize these functional categories to investigate the participation of universal stress proteins in the bacterial cellular uptake of inorganic mercury and methylmercury production, especially in anaerobic aquatic environments.

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