scholarly journals Structure and Function of the Transmembrane Domain of NsaS, an Antibiotic Sensing Histidine Kinase in Staphylococcus aureus

2018 ◽  
Vol 140 (24) ◽  
pp. 7471-7485 ◽  
Author(s):  
Manasi P. Bhate ◽  
Thomas Lemmin ◽  
Georg Kuenze ◽  
Bruk Mensa ◽  
Soumya Ganguly ◽  
...  
Keyword(s):  
Staphylococcus Aureus ◽  
Histidine Kinase ◽  
Transmembrane Domain ◽  
Structure And Function ◽  
And Function

scholarly journals Structure and Function of CC-Chemokine Receptor 5 Homologues Derived from Representative Primate Species and Subspecies of the Taxonomic Suborders Prosimii and Anthropoidea

2003 ◽  
Vol 77 (22) ◽  
pp. 12310-12318 ◽  
Author(s):  
Kevin J. Kunstman ◽  
Bridget Puffer ◽  
Bette T. Korber ◽  
Carla Kuiken ◽  
Una R. Smith ◽  
...  
Keyword(s):  
Amino Acid ◽  
Chemokine Receptor ◽  
Transmembrane Domain ◽  
Structure And Function ◽  
Primate Species ◽  
Amino Acid Substitutions ◽  
Immunodeficiency Virus ◽  
And Function ◽  
Cc Chemokine Receptor 5 ◽  
Hiv 1

ABSTRACT A chemokine receptor from the seven-transmembrane-domain G-protein-coupled receptor superfamily is an essential coreceptor for the cellular entry of human immunodeficiency virus type 1 (HIV-1) and simian immunodeficiency virus (SIV) strains. To investigate nonhuman primate CC-chemokine receptor 5 (CCR5) homologue structure and function, we amplified CCR5 DNA sequences from peripheral blood cells obtained from 24 representative species and subspecies of the primate suborders Prosimii (family Lemuridae) and Anthropoidea (families Cebidae, Callitrichidae, Cercopithecidae, Hylobatidae, and Pongidae) by PCR with primers flanking the coding region of the gene. Full-length CCR5 was inserted into pCDNA3.1, and multiple clones were sequenced to permit discrimination of both alleles. Compared to the human CCR5 sequence, the CCR5 sequences of the Lemuridae, Cebidae, and Cercopithecidae shared 87, 91 to 92, and 96 to 99% amino acid sequence homology, respectively. Amino acid substitutions tended to cluster in the amino and carboxy termini, the first transmembrane domain, and the second extracellular loop, with a pattern of species-specific changes that characterized CCR5 homologues from primates within a given family. At variance with humans, all primate species examined from the suborder Anthropoidea had amino acid substitutions at positions 13 (N to D) and 129 (V to I); the former change is critical for CD4-independent binding of SIV to CCR5. Within the Cebidae, Cercopithecidae, and Pongidae (including humans), CCR5 nucleotide similarities were 95.2 to 97.4, 98.0 to 99.5, and 98.3 to 99.3%, respectively. Despite this low genetic diversity, the phylogeny of the selected primate CCR5 homologue sequences agrees with present primate systematics, apart from some intermingling of species of the Cebidae and Cercopithecidae. Constructed HOS.CD4 cell lines expressing the entire CCR5 homologue protein from each of the Anthropoidea species and subspecies were tested for their ability to support HIV-1 and SIV entry and membrane fusion. Other than that of Cercopithecus pygerythrus, all CCR5 homologues tested were able to support both SIV and HIV-1 entry. Our results suggest that the shared structure and function of primate CCR5 homologue proteins would not impede the movement of primate immunodeficiency viruses between species.

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.

scholarly journals Exotoxins of Staphylococcus aureus

2000 ◽  
Vol 13 (1) ◽  
pp. 16-34 ◽  
Author(s):  
Martin M. Dinges ◽  
Paul M. Orwin ◽  
Patrick M. Schlievert
Keyword(s):  
Staphylococcus Aureus ◽  
Toxic Shock Syndrome ◽  
Molecular Basis ◽  
Molecular Mechanisms ◽  
Food Poisoning ◽  
Structure And Function ◽  
Toxic Shock ◽  
The Family ◽  
Toxic Shock Syndrome Toxin ◽  
And Function

SUMMARY This article reviews the literature regarding the structure and function of two types of exotoxins expressed by Staphylococcus aureus, pyrogenic toxin superantigens (PTSAgs) and hemolysins. The molecular basis of PTSAg toxicity is presented in the context of two diseases known to be caused by these exotoxins: toxic shock syndrome and staphylococcal food poisoning. The family of staphylococcal PTSAgs presently includes toxic shock syndrome toxin-1 (TSST-1) and most of the staphylococcal enterotoxins (SEs) (SEA, SEB, SEC, SED, SEE, SEG, and SEH). As the name implies, the PTSAgs are multifunctional proteins that invariably exhibit lethal activity, pyrogenicity, superantigenicity, and the capacity to induce lethal hypersensitivity to endotoxin. Other properties exhibited by one or more staphylococcal PTSAgs include emetic activity (SEs) and penetration across mucosal barriers (TSST-1). A detailed review of the molecular mechanisms underlying the toxicity of the staphylococcal hemolysins is also presented.

scholarly journals Structure and Function of the Staphylococcus aureus Bacteriophage 80α Baseplate

2017 ◽  
Vol 23 (S1) ◽  
pp. 1262-1263
Author(s):  
James L. Kizziah ◽  
Altaira D. Dearborn ◽  
Keith A. Manning ◽  
Terje Dokland
Keyword(s):  
Staphylococcus Aureus ◽  
Structure And Function ◽  
And Function

scholarly journals The Conserved Positive Charge in the Transmembrane Domain of HIV Gp41 Contributes to Its Intrinsic Preference for Trimerization

2019 ◽  
Author(s):  
Timothy Reichart ◽  
Daniel Leaman ◽  
Daniel Sands ◽  
Michael Zwick ◽  
Philip Dawson
Keyword(s):  
Hiv Infection ◽  
Positive Charge ◽  
Transmembrane Domain ◽  
Structure And Function ◽  
Model Membranes ◽  
Viral Membrane ◽  
Glycoprotein Gp41 ◽  
Tm Domain ◽  
And Function

The transmembrane (TM) domain of HIV glycoprotein gp41 anchors the envelope (Env) spike in the viral membrane and is highly conserved. The mid-span arginine 696 is particularly conserved, and the only other residue found in this position is lysine. Seeking to examine the role of this conserved positive charge in the structure and function of the gp41 TM domain, we synthesized a series of peptides corresponding to this region. Analysis of the peptides in a previously validated fluorescence assay in model membranes showed that the native TM domain is trimeric. Peptides in which the intramembrane arginine was mutated to alanine showed significantly lower trimerization propensity. In contrast, this mutation in the context of infectious pseudovirus caused only modest decreases in viral stability and infectivity. We propose a model to explain the importance of this charge to gp41 structure and to HIV infection.

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