scholarly journals The Role of Amino Acid Substitution in HepT Toward Menaquinone Isoprenoid Chain Length Definition and Lysocin E Sensitivity in Staphylococcus aureus

2020 ◽  
Vol 11 ◽  
Author(s):  
Suresh Panthee ◽  
Atmika Paudel ◽  
Hiroshi Hamamoto ◽  
Anne-Catrin Uhlemann ◽  
Kazuhisa Sekimizu
Keyword(s):  
Staphylococcus Aureus ◽  
Amino Acid ◽  
Chain Length ◽  
Amino Acid Substitution

scholarly journals Amino acid substitution reveals the role of V-shape helix on construction of yeast carboxypeptidase Y

2014 ◽  
Vol 14 (1) ◽  
pp. 27-41 ◽  
Author(s):  
Mai Makino ◽  
Takehiko Sahara ◽  
Naoki Morita ◽  
Hiroshi Ueno
Keyword(s):  
Amino Acid ◽  
Amino Acid Substitution ◽  
Carboxypeptidase Y

scholarly journals Dual Role of the Oligopeptide Permease Opp3 during Growth of Staphylococcus aureus in Milk

2009 ◽  
Vol 75 (10) ◽  
pp. 3355-3357 ◽  
Author(s):  
Elise Borez�e-Durant ◽  
Aurelia Hiron ◽  
Jean-Christophe Piard ◽  
Vincent Juillard
Keyword(s):  
Staphylococcus Aureus ◽  
Amino Acid ◽  
Nitrogen Nutrition ◽  
Dual Role ◽  
Diauxic Growth ◽  
Extracellular Proteases ◽  
Expression Levels ◽  
Oligopeptide Permease

ABSTRACT Staphylococcus aureus RN6390 presents a diauxic growth in milk, due to amino acid limitation. Inactivation of the oligopeptide permease Opp3 (dedicated to the nitrogen nutrition of the strain) not only affects the growth of the strain but also results in reduced expression levels of three major extracellular proteases.

scholarly journals Molecular Characterization of rpoBMutations Conferring Cross-Resistance to Rifamycins on Methicillin-Resistant Staphylococcus aureus

1999 ◽  
Vol 43 (11) ◽  
pp. 2813-2816 ◽  
Author(s):  
Thomas A. Wichelhaus ◽  
Volker Schäfer ◽  
Volker Brade ◽  
Boris Böddinghaus
Keyword(s):  
Staphylococcus Aureus ◽  
Amino Acid ◽  
Molecular Characterization ◽  
Amino Acid Substitution ◽  
Methicillin Resistant Staphylococcus Aureus ◽  
Cross Resistance ◽  
Methicillin Resistant ◽  
Low Level ◽  
Level Resistance

ABSTRACT Mutations of the rpoB gene conferring resistance to rifampin were analyzed in 40 methicillin-resistant Staphylococcus aureus isolates obtained from six countries. Interestingly, the majority of clinical isolates showed multiple mutations withinrpoB. The amino acid substitution 481His→Asn was the most prevalent one, capable of conferring low-level resistance on its own. Cross-resistance to rifampin, rifabutin, and rifapentine was demonstrated for all mutants identified. The level of resistance to rifamycins correlated with both the mutation position and type of amino acid substitution.

scholarly journals Role of the (p)ppGpp Synthase RSH, a RelA/SpoT Homolog, in Stringent Response and Virulence of Staphylococcus aureus

2010 ◽  
Vol 78 (5) ◽  
pp. 1873-1883 ◽  
Author(s):  
Tobias Geiger ◽  
Christiane Goerke ◽  
Michaela Fritz ◽  
Tina Schäfer ◽  
Knut Ohlsen ◽  
...  
Keyword(s):  
Staphylococcus Aureus ◽  
Amino Acid ◽  
Acid Metabolism ◽  
Stringent Response ◽  
Essential Amino Acids ◽  
Transcriptional Analysis ◽  
Wild Type ◽  
Stringent Control ◽  
Nutrient Limitations

ABSTRACT In most bacteria, nutrient limitations provoke the stringent control through the rapid synthesis of the alarmones pppGpp and ppGpp. Little is known about the stringent control in the human pathogen Staphylococcus aureus, partly due to the essentiality of the major (p)ppGpp synthase/hydrolase enzyme RSH (RelA/SpoT homolog). Here, we show that mutants defective only in the synthase domain of RSH (rsh syn) are not impaired in growth under nutrient-rich conditions. However, these mutants were more sensitive toward mupirocin and were impaired in survival when essential amino acids were depleted from the medium. RSH is the major enzyme responsible for (p)ppGpp synthesis in response to amino acid deprivation (lack of Leu/Val) or mupirocin treatment. Transcriptional analysis showed that the RSH-dependent stringent control in S. aureus is characterized by repression of genes whose products are predicted to be involved in the translation machinery and by upregulation of genes coding for enzymes involved in amino acid metabolism and transport which are controlled by the repressor CodY. Amino acid starvation also provoked stabilization of the RNAs coding for major virulence regulators, such as SaeRS and SarA, independently of RSH. In an animal model, the rsh syn mutant was shown to be less virulent than the wild type. Virulence could be restored by the introduction of a codY mutation into the rsh syn mutant. These results indicate that stringent conditions are present during infection and that RSH-dependent derepression of CodY-regulated genes is essential for virulence in S. aureus.

scholarly journals Single amino acid substitution inPlasmodium yoeliierythrocyte ligand determines its localization and controls parasite virulence

2009 ◽  
Vol 106 (17) ◽  
pp. 7167-7172 ◽  
Author(s):  
Hitoshi Otsuki ◽  
Osamu Kaneko ◽  
Amporn Thongkukiatkul ◽  
Mayumi Tachibana ◽  
Hideyuki Iriko ◽  
...  
Keyword(s):  
Amino Acid ◽  
Amino Acid Substitution ◽  
Malaria Parasite ◽  
Potential Role ◽  
Intracellular Localization ◽  
Plasmodium Yoelii ◽  
Single Amino Acid ◽  
Different Types ◽  
Erythrocyte Binding

The major virulence determinant of the rodent malaria parasite,Plasmodium yoelii, has remained unresolved since the discovery of the lethal line in the 1970s. Because virulence in this parasite correlates with the ability to invade different types of erythrocytes, we evaluated the potential role of the parasite erythrocyte binding ligand,PyEBL. We found 1 amino acid substitution in a domain responsible for intracellular trafficking between the lethal and nonlethal parasite lines and, furthermore, that the intracellular localization ofPyEBL was distinct between these lines. Genetic modification showed that this substitution was responsible not only forPyEBL localization but also the erythrocyte-type invasion preference of the parasite and subsequently its virulence in mice. This previously unrecognized mechanism for altering an invasion phenotype indicates that subtle alterations of a malaria parasite ligand can dramatically affect host–pathogen interactions and malaria virulence.

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