scholarly journals Involvement of Arg-328, Arg-334 and Arg-342 of DnaA protein in the functional interaction with acidic phospholipids

1999 ◽  
Vol 340 (2) ◽  
pp. 433-438 ◽  
Author(s):  
Yoshihiro YAMAGUCHI ◽  
Masakazu HASE ◽  
Masaki MAKISE ◽  
Shinji MIMA ◽  
Takeshi YOSHIMI ◽  
...  
Keyword(s):  
Amino Acids ◽  
Atp Binding ◽  
Amphipathic Helix ◽  
Wild Type ◽  
Functional Interaction ◽  
Basic Amino Acids ◽  
Dnaa Protein ◽  
Acidic Amino Acids ◽  
Wild Type Protein ◽  
Acidic Phospholipids

We reported previously that three basic amino acids (Arg-360, Arg-364 and Lys-372) of DnaA protein are essential for its functional interaction with cardiolipin. In this study, we examined the effect of mutation of some basic amino acids in a potential amphipathic helix (from Lys-327 to Ile-345) of DnaA protein on this interaction. ATP binding to the mutant DnaA protein, in which Arg-328, Arg-334 and Arg-342 were changed to acidic amino acids, was less inhibited by cardiolipin than that of the wild-type protein, as was the case for mutant DnaA protein with mutations of Arg-360, Arg-364 and Lys-372. A mutant DnaA protein with mutations of all six basic amino acids showed the most resistance to the inhibition of ATP binding by cardiolipin. These results suggest that Arg-328, Arg-334 and Arg-342, like Arg-360, Arg-364 and Lys-372, are also involved in the functional interaction between DnaA protein and acidic phospholipids.

scholarly journals Identification of Amino Acids Involved in the Functional Interaction between DnaA Protein and Acidic Phospholipids

2000 ◽  
Vol 275 (6) ◽  
pp. 4513-4518 ◽  
Author(s):  
Masaki Makise ◽  
Shinji Mima ◽  
Tomofusa Tsuchiya ◽  
Tohru Mizushima
Keyword(s):  
Amino Acids ◽  
Functional Interaction ◽  
Dnaa Protein ◽  
Acidic Phospholipids

scholarly journals Molecular Mechanism for Functional Interaction between DnaA Protein and Acidic Phospholipids

2000 ◽  
Vol 276 (10) ◽  
pp. 7450-7456 ◽  
Author(s):  
Masaki Makise ◽  
Shinji Mima ◽  
Tomofusa Tsuchiya ◽  
Tohru Mizushima
Keyword(s):  
Molecular Mechanism ◽  
Functional Interaction ◽  
Dnaa Protein ◽  
Acidic Phospholipids

scholarly journals Extensive mutagenesis of a transcriptional activation domain identifies single hydrophobic and acidic amino acids important for activation in vivo.

1997 ◽  
Vol 17 (1) ◽  
pp. 115-122 ◽  
Author(s):  
M B Sainz ◽  
S A Goff ◽  
V L Chandler
Keyword(s):  
Amino Acids ◽  
Amino Acid ◽  
Transcriptional Activation ◽  
Carboxyl Terminus ◽  
Wild Type ◽  
Activation Domain ◽  
Hydrophobic Residues ◽  
Transcriptional Activation Domain ◽  
Acidic Amino Acids

C1 is a transcriptional activator of genes encoding biosynthetic enzymes of the maize anthocyanin pigment pathway. C1 has an amino terminus homologous to Myb DNA-binding domains and an acidic carboxyl terminus that is a transcriptional activation domain in maize and yeast cells. To identify amino acids critical for transcriptional activation, an extensive random mutagenesis of the C1 carboxyl terminus was done. The C1 activation domain is remarkably tolerant of amino acid substitutions, as changes at 34 residues had little or no effect on transcriptional activity. These changes include introduction of helix-incompatible amino acids throughout the C1 activation domain and alteration of most single acidic amino acids, suggesting that a previously postulated amphipathic alpha-helix is not required for activation. Substitutions at two positions revealed amino acids important for transcriptional activation. Replacement of leucine 253 with a proline or glutamine resulted in approximately 10% of wild-type transcriptional activation. Leucine 253 is in a region of C1 in which several hydrophobic residues align with residues important for transcriptional activation by the herpes simplex virus VP16 protein. However, changes at all other hydrophobic residues in C1 indicate that none are critical for C1 transcriptional activation. The other important amino acid in C1 is aspartate 262, as a change to valine resulted in only 24% of wild-type transcriptional activation. Comparison of our C1 results with those from VP16 reveal substantial differences in which amino acids are required for transcriptional activation in vivo by these two acidic activation domains.

scholarly journals Structural factors influencing the reaction rates of 4-aryloxy-7-nitrobenzofurazans with amino acids

2004 ◽  
Vol 2 (4) ◽  
pp. 672-685 ◽  
Author(s):  
Marioara Bem ◽  
Marilena Vasilescu ◽  
Miron Caproiu ◽  
Constantin Draghici ◽  
Adrian Beteringhe ◽  
...  
Keyword(s):  
Amino Acids ◽  
Room Temperature ◽  
Reaction Rates ◽  
Structural Factors ◽  
Basic Amino Acids ◽  
Interesting Observation ◽  
Neutral Amino Acids ◽  
Acidic Amino Acids ◽  
Factors Influencing ◽  
Snar Reaction

AbstractAn interesting observation was made when studying the SNAr reaction between several 4-aryloxy-7-nitrobenzofurazans (2) and several amino acids leading to the apparition of detectable fluorescence from the substitution products3. Acidic amino acids reacted very slowly=while basic amino acids react fastest with2 having an unsubstituted phenyl or a 4-formyl-phenyl Ar group. Amongst neutral amino acids, proline reacts fastest at room temperature after 100 min. With2 having a methoxy-subtituted Ar group.

scholarly journals Involvement of Arg-328, Arg-334 and Arg-342 of DnaA protein in the functional interaction with acidic phospholipids

1999 ◽  
Vol 340 (2) ◽  
pp. 433 ◽  
Author(s):  
Yoshihiro YAMAGUCHI ◽  
Masakazu HASE ◽  
Masaki MAKISE ◽  
Shinji MIMA ◽  
Takeshi YOSHIMI ◽  
...  
Keyword(s):  
Functional Interaction ◽  
Dnaa Protein ◽  
Acidic Phospholipids

scholarly journals Basic Residues in the Mason-Pfizer Monkey Virus Gag Matrix Domain Regulate Intracellular Trafficking and Capsid-Membrane Interactions

2007 ◽  
Vol 81 (17) ◽  
pp. 8977-8988 ◽  
Author(s):  
Elizabeth Stansell ◽  
Robert Apkarian ◽  
Sarka Haubova ◽  
William E. Diehl ◽  
Ewan M. Tytler ◽  
...  
Keyword(s):  
Amino Acids ◽  
Plasma Membrane ◽  
Intracellular Transport ◽  
Wild Type ◽  
Membrane Interactions ◽  
Cortical Actin ◽  
Basic Amino Acids ◽  
Gag Polyprotein ◽  
The Matrix ◽  
Arginine Residues

ABSTRACT Mason-Pfizer monkey virus (M-PMV) capsids that have assembled in the cytoplasm must be transported to and associate with the plasma membrane prior to being enveloped by a lipid bilayer during viral release. Structural studies have identified a positive-charge density on the membrane-proximal surface of the matrix (MA) protein component of the Gag polyprotein. To investigate if basic amino acids in MA play a role in intracellular transport and capsid-membrane interactions, mutants were constructed in which lysine and arginine residues (R10, K16, K20, R22, K25, K27, K33, and K39) potentially exposed on the capsid surface were replaced singly and in pairs by alanine. A majority of the charge substitution mutants were released less efficiently than the wild type. Electron microscopy of mutant Gag-expressing cells revealed four distinct phenotypes: K16A and K20A immature capsids accumulated on and budded into intracellular vesicles; R10A, K27A, and R22A capsid transport was arrested at the cellular cortical actin network, while K25A immature capsids were dispersed throughout the cytoplasm and appeared to be defective at an earlier stage of intracellular transport; and the remaining mutant (K33A and K39A) capsids accumulated at the inner surface of the plasma membrane. All mutants that released virions exhibited near-wild-type infectivity in a single-round assay. Thus, basic amino acids in the M-PMV MA define both cellular location and efficiency of virus release.

scholarly journals Effect of Cleavage Mutants on Syncytium Formation Directed by the Wild-Type Fusion Protein of Newcastle Disease Virus

1998 ◽  
Vol 72 (5) ◽  
pp. 3789-3795 ◽  
Author(s):  
Zengji Li ◽  
Theresa Sergel ◽  
Enal Razvi ◽  
Trudy Morrison
Keyword(s):  
Amino Acids ◽  
Newcastle Disease Virus ◽  
Disease Virus ◽  
Newcastle Disease ◽  
Syncytium Formation ◽  
Dominant Negative ◽  
Wild Type ◽  
F Protein ◽  
Type Protein ◽  
Wild Type Protein

ABSTRACT The effects of Newcastle disease virus (NDV) fusion (F) glycoprotein cleavage mutants on the cleavage and syncytium-forming activity of the wild-type F protein were examined. F protein cleavage mutants were made by altering amino acids in the furin recognition region (amino acids 112 to 116) in the F protein of a virulent strain of NDV. Four mutants were made: Q114P replaced the glutamine residue with proline; K115G replaced lysine with glycine; double mutant K115G, R113G replaced both a lysine and an arginine with glycine residues; and a triple mutant, R112G, K115G, F117L, replaced three amino acids to mimic the sequence found in avirulent strains of NDV. All mutants except Q114P were cleavage negative and fusion negative. However, addition of exogenous trypsin cleaved all mutant F proteins and activated fusion. As expected for an oligomeric protein, the fusion-negative mutants had a dominant negative phenotype: cotransfection of wild-type and mutant F protein cDNAs resulted in an inhibition of syncytium formation. The presence of the mutant F protein did not inhibit cleavage of the wild-type protein. Furthermore, evidence is presented that suggests that the mutant protein and the wild-type protein formed heterooligomers. By measuring the syncytium-forming activity of the wild-type protein at various ratios of expression of mutant and wild-type protein, results were obtained that are most consistent with the notion that the size of the functionally active NDV F protein in these assays is a single oligomer, likely a trimer. That a larger oligomer, containing a mix of both wild-type and mutant F proteins, has partial activity cannot, however, be ruled out.

Interfacial basic amino acids increase the lipid affinity of class A amphipathic helix: Evidence for snorkel hypothesis by 13C-NMR spectroscopy

Peptides ◽  
1994 ◽  
pp. 370-372
Author(s):  
S. Lund-Katz ◽  
M.C. Phillips ◽  
V.K. Mishra ◽  
Y.V. Venkatachalapathi ◽  
J.P. Segrest ◽  
...  
Keyword(s):  
Amino Acids ◽  
Nmr Spectroscopy ◽  
13C Nmr ◽  
13C Nmr Spectroscopy ◽  
Amphipathic Helix ◽  
Basic Amino Acids ◽  
Class A

scholarly journals Members of the Conserved DedA Family Are Likely Membrane Transporters and Are Required for Drug Resistance in Escherichia coli

2013 ◽  
Vol 58 (2) ◽  
pp. 923-930 ◽  
Author(s):  
Sujeet Kumar ◽  
William T. Doerrler
Keyword(s):  
Escherichia Coli ◽  
Amino Acids ◽  
Drug Resistance ◽  
Public Health Problem ◽  
Membrane Transporters ◽  
Wild Type ◽  
Content Type ◽  
E Coli ◽  
Acidic Amino Acids ◽  
Genes Encoding

ABSTRACTBacterial resistance to antibiotics and biocides is an increasing public health problem. Genes encoding integral membrane proteins belonging to the DedA family are present in most bacterial genomes, includingEscherichia coli. AnE. colistrain lacking partially redundant DedA family genesyqjAandyghB(strain BC202) displays temperature sensitivity and cell division defects. These phenotypes can be corrected by overexpression ofmdfA, an Na+-K+/H+antiporter of the major facilitator superfamily. We show that BC202 is hypersensitive to several biocides and cationic compounds that are known substrates of several multidrug resistance transporters, including MdfA, EmrE, and AcrB. The introduction of deletions of genes encoding these drug transporters into BC202 results in additional sensitivity. Expression of wild-typeyghBoryqjAcan restore drug resistance, but this is eliminated upon mutation of two membrane-embedded acidic amino acids (E39 or D51 in either protein). This dependence upon membrane-embedded acidic amino acids is a hallmark of proton-dependent antiporters. Overexpression ofmdfAin BC202 or artificially restoring proton motive force (PMF) restores wild-type resistance to substrates of MdfA as well as other drug resistance transporters such as EmrE and AcrAB. These results suggest that YqjA and YghB may be membrane transporters required for PMF-dependent drug efflux inE. coli.

Mutations to Gly2370, Gly2373 or Gly2375 in malignant hyperthermia domain 2 decrease caffeine and cresol sensitivity of the rabbit skeletal-muscle Ca2+-release channel (ryanodine receptor isoform 1)

2001 ◽  
Vol 360 (1) ◽  
pp. 97-105 ◽  
Author(s):  
Guo Guang DU ◽  
Hideto OYAMADA ◽  
Vijay K. KHANNA ◽  
David H. MacLENNAN
Keyword(s):  
Skeletal Muscle ◽  
Amino Acids ◽  
Malignant Hyperthermia ◽  
Ryanodine Receptor ◽  
Atp Binding ◽  
Regulatory Domain ◽  
Wild Type ◽  
Release Channel ◽  
Binding Motifs ◽  
Channel Opening

Mutations G2370A, G2372A, G2373A, G2375A, Y3937A, S3938A, G3939A and K3940A were made in two potential ATP-binding motifs (amino acids 2370–2375 and 3937–3940) in the Ca2+-release channel of skeletal-muscle sarcoplasmic reticulum (ryanodine receptor or RyR1). Activation of [3H]ryanodine binding by Ca2+, caffeine and ATP (adenosine 5′-[β,γ-methylene]triphosphate, AMP-PCP) was used as an assay for channel opening, since ryanodine binds only to open channels. Caffeine-sensitivity of channel opening was also assayed by caffeine-induced Ca2+ release in HEK-293 cells expressing wild-type and mutant channels. Equilibrium [3H]ryanodine-binding properties and EC50 values for Ca2+ activation of high-affinity [3H]ryanodine binding were similar between wild-type RyR1 and mutants. In the presence of 1mM AMP-PCP, Ca2+-activation curves were shifted to higher affinity and maximal binding was increased to a similar extent for wild-type RyR1 and mutants. ATP sensitivity of channel opening was also similar for wild-type and mutants. These observations apparently rule out sequences 2370–2375 and 3937–3940 as ATP-binding motifs. Caffeine or 4-chloro-m-cresol sensitivity, however, was decreased in mutants G2370A, G2373A and G2375A, whereas the other mutants retained normal sensitivity. Amino acids 2370–2375 lie within a sequence (amino acids 2163–2458) in which some eight RyR1 mutations have been associated with malignant hyperthermia and shown to be hypersensitive to caffeine and 4-chloro-m-cresol activation. By contrast, mutants G2370A, G2373A and G2375A are hyposensitive to caffeine and 4-chloro-m-cresol. Thus amino acids 2163–2458 form a regulatory domain (malignant hyperthermia regulatory domain 2) that regulates caffeine and 4-chloro-m-cresol sensitivity of RyR1.

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