Non-specific Interaction of Fpg Protein from Escherichia coli with DNA. Affinity and Dynamics Study

2000 ◽  
Vol 28 (5) ◽  
pp. A164-A164
Author(s):  
O. S. Fedorova ◽  
V. V. Koval ◽  
A. A. Ishchenko ◽  
K. T. Douglas ◽  
G. A. Nevinsky
Keyword(s):  
Escherichia Coli ◽  
Specific Interaction

scholarly journals Effects of distortions by A-tracts of promoter B-DNA spacer region on the kinetics of open complex formation by Escherichia coli RNA polymerase.

2003 ◽  
Vol 50 (4) ◽  
pp. 909-920 ◽  
Author(s):  
Iwona K Kolasa ◽  
Tomasz Łoziński ◽  
Kazimierz L Wierzchowski
Keyword(s):  
Escherichia Coli ◽  
Rna Polymerase ◽  
Transcription Initiation ◽  
Specific Interaction ◽  
Structural Data ◽  
Structural Morphology ◽  
Promoter Dna ◽  
Sigma Subunit ◽  
Kinetics Of

A-tracts in DNA due to their structural morphology distinctly different from the canonical B-DNA form play an important role in specific recognition of bacterial upstream promoter elements by the carboxyl terminal domain of RNA polymerase alpha subunit and, in turn, in the process of transcription initiation. They are only rarely found in the spacer promoter regions separating the -35 and -10 recognition hexamers. At present, the nature of the protein-DNA contacts formed between RNA polymerase and promoter DNA in transcription initiation can only be inferred from low resolution structural data and mutational and crosslinking experiments. To probe these contacts further, we constructed derivatives of a model Pa promoter bearing in the spacer region one or two An (n = 5 or 6) tracts, in phase with the DNA helical repeat, and studied the effects of thereby induced perturbation of promoter DNA structure on the kinetics of open complex (RPo) formation in vitro by Escherichia coli RNA polymerase. We found that the overall second-order rate constant ka of RPo formation, relative to that at the control promoter, was strongly reduced by one to two orders of magnitude only when the A-tracts were located in the nontemplate strand. A particularly strong 30-fold down effect on ka was exerted by nontemplate A-tracts in the -10 extended promoter region, where an involvement of nontemplate TG (-14, -15) sequence in a specific interaction with region 3 of sigma-subunit is postulated. A-tracts in the latter location caused also 3-fold slower isomerization of the first closed transcription complex into the intermediate one that precedes formation of RPo, and led to two-fold faster dissociation of the latter. All these findings are discussed in relation to recent structural and kinetic models of RPo formation.

Large-scale purification, oligomerization equilibria, and specific interaction of the LexA repressor of Escherichia coli

Biochemistry ◽  
1985 ◽  
Vol 24 (11) ◽  
pp. 2812-2818 ◽  
Author(s):  
M. Schnarr ◽  
J. Pouyet ◽  
M. Granger-Schnarr ◽  
M. Daune
Keyword(s):  
Escherichia Coli ◽  
Large Scale ◽  
Specific Interaction ◽  
Lexa Repressor

scholarly journals Specific DNA Binding and Regulation of Its Own Expression by the AidB Protein in Escherichia coli

2010 ◽  
Vol 192 (23) ◽  
pp. 6136-6142 ◽  
Author(s):  
Valentina Rippa ◽  
Angela Amoresano ◽  
Carla Esposito ◽  
Paolo Landini ◽  
Michael Volkert ◽  
...  
Keyword(s):  
Escherichia Coli ◽  
Dna Binding ◽  
Alkylating Agents ◽  
Specific Interaction ◽  
Domain Architecture ◽  
Binding Activity ◽  
Dna Binding Activity ◽  
Preferential Binding

ABSTRACT Upon exposure to alkylating agents, Escherichia coli increases expression of aidB along with three genes (ada, alkA, and alkB) that encode DNA repair proteins. While the biological roles of the Ada, AlkA, and AlkB proteins have been defined, despite many efforts, the molecular functions of AidB remain largely unknown. In this study, we focused on the biological role of the AidB protein, and we demonstrated that AidB shows preferential binding to a DNA region that includes the upstream element of its own promoter, PaidB. The physiological significance of this specific interaction was investigated by in vivo gene expression assays, demonstrating that AidB can repress its own synthesis during normal cell growth. We also showed that the domain architecture of AidB is related to the different functions of the protein: the N-terminal region, comprising the first 439 amino acids (AidB “I-III”), possesses FAD-dependent dehydrogenase activity, while its C-terminal domain, corresponding to residues 440 to 541 (AidB “IV”), displays DNA binding activity and can negatively regulate the expression of its own gene in vivo. Our results define a novel role in gene regulation for the AidB protein and underline its multifunctional nature.

Novel evidence for the specific interaction between cholesterol and α-haemolysin of Escherichia coli

2014 ◽  
Vol 458 (3) ◽  
pp. 481-489 ◽  
Author(s):  
Romina F. Vazquez ◽  
Sabina M. Maté ◽  
Laura S. Bakás ◽  
Marisa M. Fernández ◽  
Emilio L. Malchiodi ◽  
...  
Keyword(s):  
Escherichia Coli ◽  
Specific Interaction ◽  
Conformational State ◽  
First Time

The present study shows, for the first time, the interaction of HlyA with cholesterol. This interaction seems to favour a conformational state of the protein that allows its correct insertion into the membrane and its further oligomerization to form pores.

scholarly journals Opsonin-independent ligation of Fc gamma receptors. The 3G8-bearing receptors on neutrophils mediate the phagocytosis of concanavalin A-treated erythrocytes and nonopsonized Escherichia coli.

1987 ◽  
Vol 166 (6) ◽  
pp. 1798-1813 ◽  
Author(s):  
J E Salmon ◽  
S Kapur ◽  
R P Kimberly
Keyword(s):  
Escherichia Coli ◽  
Cell Surface ◽  
Specific Interaction ◽  
Human Neutrophils ◽  
Con A ◽  
Fc Gamma Receptor ◽  
Surface Attachment ◽  
E Coli ◽  
Gamma Receptor ◽  
Mannose Binding

We report that phagocytosis by human neutrophils of Con A-treated erythrocytes (E-Con A) and nonopsonized Escherichia coli with mannose-binding adhesions is mediated by the Fc gamma receptor bearing the 3G8 epitope. Modulation of Fc receptors by pretreating with aggregated-IgG or with 3G8 anti-Fc gamma receptor mAb markedly inhibited internalization of E-Con A and E. coli without altering their cell surface attachment. Phagocytosis of these probes was specifically blocked by alpha-methylmannoside and D-mannose and not by other monosaccharides. Thus, recognition of E-Con A and E. coli by the Fc receptor is dependent upon the mannose-specific interaction with lectin or lectin-like adhesions. These data demonstrate that ligands other than the classical IgG opsonins can bind to classical immune receptors for IgG through lectin-carbohydrate interactions.

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