scholarly journals GyrB mutations in Staphylococcus aureus strains resistant to cyclothialidine, coumermycin, and novobiocin.

1996 ◽  
Vol 40 (4) ◽  
pp. 1060-1062 ◽  
Author(s):  
M Stieger ◽  
P Angehrn ◽  
B Wohlgensinger ◽  
H Gmünder
Keyword(s):  
Staphylococcus Aureus ◽  
Binding Mode ◽  
Atp Binding ◽  
Subunit Gene ◽  
Binding Region ◽  
B Subunit ◽  
B Subunits ◽  
Atp Binding And Hydrolysis

The sequence of the gyrase B subunit gene from Staphylococcus aureus strains resistant to the gyrase B subunit inhibitors cyclothialidine, coumermycin, and novobiocin has been determined. The residues altered in the resistant gyrase B subunits map to the ATP-binding region, suggesting that the drugs inhibit ATP binding and hydrolysis. The pattern of cross-resistances indicates that the detailed binding mode of the compounds differs.

ISOLATION AND CHARACTERIZATION OF THE GENES FOR THE a AND b SUBUNITS OF HUMAN COAGULATION FACTOR XIII

1987 ◽  
Author(s):  
A Ichinose ◽  
R E Bottenus ◽  
K R Loeb ◽  
E W Davie
Keyword(s):  
Amino Acid ◽  
Factor Xiii ◽  
Coagulation Factor ◽  
Amino Acid Sequences ◽  
Binding Region ◽  
Recombinant Phage ◽  
B Subunit ◽  
Isolation And Characterization ◽  
A Subunit ◽  
B Subunits

Factor XIII (plasma transglutaminase, fibrin stabilizing factor) is a plasma protein that plays an important role in the final stages of blood coagulation and fibrinolysis. The molecule occurs in blood as a tetramer (a2b2) consisting of two a. subunits and two b subunits. Recently, we have determined the amino acid sequences for both the a. and b subunits of human factor XIII by a combination of cDNA cloning and amino acid sequence analysis. cDNAs coding for the a (3.8 Kb) and b (2.2 Kb) subunits were used for the screening of human genomic DNA libraries. Among 12 × 106 recombinant phage, ∼30 have been shown to contain the sequences for the a subunit and ∼10 have been shown to contain the gene for the b subunit of factor XIII. The clones coding for the a. subunit span ∼90 Kb and have been characterized by restriction mapping. Southern blotting, and DNA sequencing. Both 5’ and 3’ ends of the genomic clones correspond to the 5’ and 3’portions of the cDNA for the a.subunit of factor XIII. The DNA sequence revealed that the activation peptide released ^thrombin (amino acid residues 137), the first putative Ca2+ binding region (around residue 251), the active Site Cys (amino acid residue 314), and the second putative Ca2+ binding region (around residue 473) are encoded by separate exons. Accordingly, the intervening sequences may separate the a subunit into functional and structural domains. The gene organization for the b subunit will also be presented. (Supported by NIH Grant HL 16919.)

scholarly journals The Buzz about ADP-Ribosylation Toxins from Paenibacillus larvae, the Causative Agent of American Foulbrood in Honey Bees

Toxins ◽  
2021 ◽  
Vol 13 (2) ◽  
pp. 151
Author(s):  
Julia Ebeling ◽  
Anne Fünfhaus ◽  
Elke Genersch
Keyword(s):  
Virulence Factors ◽  
Structural Similarity ◽  
Paenibacillus Larvae ◽  
American Foulbrood ◽  
Rho Proteins ◽  
Experimental Proof ◽  
Host Interactions ◽  
B Subunit ◽  
Cellular Target ◽  
B Subunits

The Gram-positive, spore-forming bacterium Paenibacillus larvae is the etiological agent of American Foulbrood, a highly contagious and often fatal honey bee brood disease. The species P. larvae comprises five so-called ERIC-genotypes which differ in virulence and pathogenesis strategies. In the past two decades, the identification and characterization of several P. larvae virulence factors have led to considerable progress in understanding the molecular basis of pathogen-host-interactions during P. larvae infections. Among these virulence factors are three ADP-ribosylating AB-toxins, Plx1, Plx2, and C3larvin. Plx1 is a phage-born toxin highly homologous to the pierisin-like AB-toxins expressed by the whites-and-yellows family Pieridae (Lepidoptera, Insecta) and to scabin expressed by the plant pathogen Streptomyces scabiei. These toxins ADP-ribosylate DNA and thus induce apoptosis. While the presumed cellular target of Plx1 still awaits final experimental proof, the classification of the A subunits of the binary AB-toxins Plx2 and C3larvin as typical C3-like toxins, which ADP-ribosylate Rho-proteins, has been confirmed experimentally. Normally, C3-exoenzymes do not occur together with a B subunit partner, but as single domain toxins. Interestingly, the B subunits of the two P. larvae C3-like toxins are homologous to the B-subunits of C2-like toxins with striking structural similarity to the PA-63 protomer of Bacillus anthracis.

Primary mediastinal paraganglioma associated with a familial variant in the succinate dehydrogenase B subunit gene

2017 ◽  
Vol 117 (2) ◽  
pp. 160-162 ◽  
Author(s):  
Nardin Samuel ◽  
Resham Ejaz ◽  
Josh Silver ◽  
Shereen Ezzat ◽  
Robert J. Cusimano ◽  
...  
Keyword(s):  
Succinate Dehydrogenase ◽  
Subunit Gene ◽  
B Subunit ◽  
Mediastinal Paraganglioma

scholarly journals Biochemical and structural characterization of the novel sialic acid-binding site of Escherichia coli heat-labile enterotoxin LT-IIb

2016 ◽  
Vol 473 (21) ◽  
pp. 3923-3936 ◽  
Author(s):  
Dani Zalem ◽  
João P. Ribeiro ◽  
Annabelle Varrot ◽  
Michael Lebens ◽  
Anne Imberty ◽  
...  
Keyword(s):  
Escherichia Coli ◽  
Binding Site ◽  
Cholera Toxin ◽  
Carbohydrate Binding ◽  
Type I ◽  
Type Ii ◽  
E Coli ◽  
B Subunit ◽  
Heat Labile ◽  
B Subunits

The structurally related AB5-type heat-labile enterotoxins of Escherichia coli and Vibrio cholerae are classified into two major types. The type I group includes cholera toxin (CT) and E. coli LT-I, whereas the type II subfamily comprises LT-IIa, LT-IIb and LT-IIc. The carbohydrate-binding specificities of LT-IIa, LT-IIb and LT-IIc are distinctive from those of cholera toxin and E. coli LT-I. Whereas CT and LT-I bind primarily to the GM1 ganglioside, LT-IIa binds to gangliosides GD1a, GD1b and GM1, LT-IIb binds to the GD1a and GT1b gangliosides, and LT-IIc binds to GM1, GM2, GM3 and GD1a. These previous studies of the binding properties of type II B-subunits have been focused on ganglio core chain gangliosides. To further define the carbohydrate binding specificity of LT-IIb B-subunits, we have investigated its binding to a collection of gangliosides and non-acid glycosphingolipids with different core chains. A high-affinity binding of LT-IIb B-subunits to gangliosides with a neolacto core chain, such as Neu5Gcα3- and Neu5Acα3-neolactohexaosylceramide, and Neu5Gcα3- and Neu5Acα3-neolactooctaosylceramide was detected. An LT-IIb-binding ganglioside was isolated from human small intestine and characterized as Neu5Acα3-neolactohexaosylceramide. The crystal structure of the B-subunit of LT-IIb with the pentasaccharide moiety of Neu5Acα3-neolactotetraosylceramide (Neu5Ac-nLT: Neu5Acα3Galβ4GlcNAcβ3Galβ4Glc) was determined providing the first information for a sialic-binding site in this subfamily, with clear differences from that of CT and LT-I.

Structural and functional studies of SAV1707 from Staphylococcus aureus elucidate its distinct metal-dependent activity and a crucial residue for catalysis

2021 ◽  
Vol 77 (5) ◽  
pp. 587-598
Author(s):  
Dong-Gyun Kim ◽  
Kyu-Yeon Lee ◽  
Sang Jae Lee ◽  
Seung-Ho Cheon ◽  
Yuri Choi ◽  
...  
Keyword(s):  
Staphylococcus Aureus ◽  
Metal Binding ◽  
Binding Mode ◽  
Structure And Function ◽  
Functional Study ◽  
Functional Studies ◽  
Dependent Endonuclease ◽  
Metal Selectivity ◽  
Metal Binding Domain ◽  
And Function

The metallo-β-lactamase fold is the most abundant metal-binding domain found in two major kingdoms: bacteria and archaea. Despite the rapid growth in genomic information, most of these enzymes, which may play critical roles in cellular metabolism, remain uncharacterized in terms of structure and function. In this study, X-ray crystal structures of SAV1707, a hypothetical metalloenzyme from Staphylococcus aureus, and its complex with cAMP are reported at high resolutions of 2.05 and 1.55 Å, respectively, with a detailed atomic description. Through a functional study, it was verified that SAV1707 has Ni2+-dependent phosphodiesterase activity and Mn2+-dependent endonuclease activity, revealing a different metal selectivity depending on the reaction. In addition, the crystal structure of cAMP-bound SAV1707 shows a unique snapshot of cAMP that reveals the binding mode of the intermediate, and a key residue Phe511 that forms π–π interactions with cAMP was verified as contributing to substrate recognition by functional studies of its mutant. Overall, these findings characterized the relationship between the structure and function of SAV1707 and may provide further understanding of metalloenzymes possessing the metallo-β-lactamase fold.

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