scholarly journals Functional and Structural Role of the Cytochrome b Subunit of the Membrane-Bound Hydrogenase Complex of Alcaligenes Eutrophus H16

1997 ◽  
Vol 248 (1) ◽  
pp. 179-186 ◽  
Author(s):  
Michael Bernhard ◽  
Bruna Benelli ◽  
Alejandro Hochkoeppler ◽  
Davide Zannoni ◽  
Barbel Friedrich
Keyword(s):  
Cytochrome B ◽  
Alcaligenes Eutrophus ◽  
Structural Role ◽  
B Subunit ◽  
Alcaligenes Eutrophus H16 ◽  
Membrane Bound

scholarly journals Biochemical and Genetic Characterization of the Enterococcus faecalis Oxaloacetate Decarboxylase Complex

2013 ◽  
Vol 79 (9) ◽  
pp. 2882-2890 ◽  
Author(s):  
Guillermo D. Repizo ◽  
Víctor S. Blancato ◽  
Pablo Mortera ◽  
Juke S. Lolkema ◽  
Christian Magni
Keyword(s):  
Enterococcus Faecalis ◽  
Soluble Form ◽  
The Novel ◽  
Oxaloacetate Decarboxylase ◽  
Content Type ◽  
Membrane Pump ◽  
B Subunit ◽  
Single Deletion ◽  
Membrane Bound

ABSTRACTEnterococcus faecalisencodes a biotin-dependent oxaloacetate decarboxylase (OAD), which is constituted by four subunits:E. faecaliscarboxyltransferase subunit OadA (termedEf-A), membrane pumpEf-B, biotin acceptor proteinEf-D, and the novel subunitEf-H. Our results show that inE. faecalis, subunitsEf-A,Ef-D, andEf-H form a cytoplasmic soluble complex (termedEf-AHD) which is also associated with the membrane. In order to characterize the role of the novelEf-H subunit, coexpression ofoadgenes was performed inEscherichia coli, showing that this subunit is vital forEf-A andEf-D interaction. Diminished growth of theoadAandoadDsingle deletion mutants in citrate-supplemented medium indicated that the activity of the complex is essential for citrate utilization. Remarkably, theoadB-deficient strain was still capable of growing to wild-type levels but with a delay during the citrate-consuming phase, suggesting that the solubleEf-AHD complex is functional inE. faecalis.These results suggest that theEf-AHD complex is active in its soluble form, and that it is capable of interacting in a dynamic way with the membrane-boundEf-B subunit to achieve its maximal alkalinization capacity during citrate fermentation.

scholarly journals Role of hydrogen in the activation and regulation of hydrogen oxidation by the soluble hydrogenase from Alcaligenes eutrophus H16

1988 ◽  
Vol 254 (2) ◽  
pp. 463-468 ◽  
Author(s):  
M R Hyman ◽  
C A Fox ◽  
D J Arp
Keyword(s):  
Hydrogen Oxidation ◽  
Alcaligenes Eutrophus ◽  
Constant Concentration ◽  
Activation Kinetics ◽  
Diaphorase Activity ◽  
Alcaligenes Eutrophus H16 ◽  
Level Of Activity ◽  
H2 Oxidation ◽  
Kinetics Of

The activation kinetics of the H2-oxidizing activity of the soluble hydrogenase from Alcaligenes eutrophus H16 were investigated. Activation with Na2S2O4 plus 101 kPa H2 resulted in a rapid increase in activity over 1 h and constant activity after 3 h incubation. Less-stable activations were achieved if enzyme was incubated with Na2S2O4 under 1 kPa H2 or 101 kPa N2. The enzyme could also be partly activated either with NADH alone or with H2 alone. The level of activity obtained with both 101 kPa H2 and NADH present was greater than that obtained with either 101 kPa H2 or NADH alone. Activation with H2 plus NADH was virtually independent of NADH concentration but highly dependent on H2 concentration. The effects of various concentrations of H2 and constant concentration of NADH on the level of activation were the same whether H2 oxidation was assayed by H2-dependent Methylene Blue or NAD+ reduction. Diaphorase activity did not require activation and was little affected by the treatments that activated H2-oxidizing activity. The results suggest that H2 plays an important role in regulating the level of H2-oxidizing activity in this soluble hydrogenase.

scholarly journals A gene complex coding for the membrane-bound hydrogenase of Alcaligenes eutrophus H16.

1992 ◽  
Vol 174 (19) ◽  
pp. 6277-6289 ◽  
Author(s):  
C Kortlüke ◽  
K Horstmann ◽  
E Schwartz ◽  
M Rohde ◽  
R Binsack ◽  
...  
Keyword(s):  
Alcaligenes Eutrophus ◽  
Gene Complex ◽  
Alcaligenes Eutrophus H16 ◽  
Membrane Bound

scholarly journals Role of the b subunit of the Escherichia coli proton-translocating ATPase. A mutagenic analysis.

1985 ◽  
Vol 260 (13) ◽  
pp. 8182-8187 ◽  
Author(s):  
A C Porter ◽  
C Kumamoto ◽  
K Aldape ◽  
R D Simoni
Keyword(s):  
Escherichia Coli ◽  
B Subunit ◽  
Proton Translocating Atpase

The Role of Solid Springer in Masonry Vault

2010 ◽  
Vol 133-134 ◽  
pp. 349-354 ◽  
Author(s):  
Vittorio Ceradini ◽  
Michele Candela ◽  
Roberta Fonti
Keyword(s):  
Scientific Research ◽  
Evolution Process ◽  
Limit Case ◽  
Structural Configuration ◽  
Structural Role ◽  
Different Ages ◽  
Building Component ◽  
And Function ◽  
Technical Rules

During a scientific research, directed to understand the structural role of some particular masonry elements, noticeable in covering structures like vault and dome, we searched the technical rules and function of these elements. We verified that in literature there is no specific documentation about these elements and its mechanic purposes. The study was directed to recognize the most representatives architectures in different ages, and to identify the construction technique’s evolution process of this particular arc-double or thickening of arc that we arrived to identify as a necessary building component to give balance in particular structural configuration. This process put down roots from the roman ancient age, until baroque age, where the most original applications of this regulation were placed. From Pantheon to the limit case of St. Filippo Neri chapel, the covers’ structures springer angle studied was analyzed together with its relation to plan, sections and elevation of all buildings. Therefore, if these elements are well-performed, they follow precise constructive patterns that this article would like to identify and show.

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