scholarly journals A single amino acid change in Escherichia coli glycerol kinase abolishes glucose control of glycerol utilization in vivo.

1996 ◽  
Vol 178 (10) ◽  
pp. 2846-2852 ◽  
Author(s):  
D W Pettigrew ◽  
W Z Liu ◽  
C Holmes ◽  
N D Meadow ◽  
S Roseman
Keyword(s):  
Escherichia Coli ◽  
Amino Acid ◽  
Glucose Control ◽  
Amino Acid Change ◽  
Glycerol Kinase ◽  
Single Amino Acid ◽  
Single Amino Acid Change ◽  
Glycerol Utilization

scholarly journals A Point Mutation in the Rhesus Rotavirus VP4 Protein Generated through a Rotavirus Reverse Genetics System Attenuates Biliary Atresia in the Murine Model

2017 ◽  
Vol 91 (15) ◽  
Author(s):  
Sujit K. Mohanty ◽  
Bryan Donnelly ◽  
Phylicia Dupree ◽  
Inna Lobeck ◽  
Sarah Mowery ◽  
...  
Keyword(s):  
Amino Acid ◽  
Biliary Atresia ◽  
Amino Acid Change ◽  
Reverse Genetics ◽  
Single Amino Acid ◽  
Wild Type ◽  
Neonatal Mice ◽  
Single Amino Acid Change

ABSTRACT Rotavirus infection is one of the most common causes of diarrheal illness in humans. In neonatal mice, rhesus rotavirus (RRV) can induce biliary atresia (BA), a disease resulting in inflammatory obstruction of the extrahepatic biliary tract and intrahepatic bile ducts. We previously showed that the amino acid arginine (R) within the sequence SRL (amino acids 445 to 447) in the RRV VP4 protein is required for viral binding and entry into biliary epithelial cells. To determine if this single amino acid (R) influences the pathogenicity of the virus, we generated a recombinant virus with a single amino acid mutation at this site through a reverse genetics system. We demonstrated that the RRV mutant (RRVVP4-R446G) produced less symptomatology and replicated to lower titers both in vivo and in vitro than those seen with wild-type RRV, with reduced binding in cholangiocytes. Our results demonstrate that a single amino acid change in the RRV VP4 gene influences cholangiocyte tropism and reduces pathogenicity in mice. IMPORTANCE Rotavirus is the leading cause of diarrhea in humans. Rhesus rotavirus (RRV) can also lead to biliary atresia (a neonatal human disease) in mice. We developed a reverse genetics system to create a mutant of RRV (RRVVP4-R446G) with a single amino acid change in the VP4 protein compared to that of wild-type RRV. In vitro, the mutant virus had reduced binding and infectivity in cholangiocytes. In vivo, it produced fewer symptoms and lower mortality in neonatal mice, resulting in an attenuated form of biliary atresia.

scholarly journals Expression of the HSV-1 capsid protein VP19C in Escherichia coli: A single amino acid change overcomes an expression block of the full-length polypeptide

2011 ◽  
Vol 77 (1) ◽  
pp. 80-85 ◽  
Author(s):  
Brandon W. Henson ◽  
Nicole Johnson ◽  
Alakesh Bera ◽  
Mercy E. Okoye ◽  
Keshal Viren Desai ◽  
...  
Keyword(s):  
Escherichia Coli ◽  
Amino Acid ◽  
Capsid Protein ◽  
Amino Acid Change ◽  
Full Length ◽  
Single Amino Acid ◽  
Single Amino Acid Change ◽  
Hsv 1

scholarly journals FlexibilityIn Vitroof Amino Acid 226 in the Receptor-Binding Site of an H9 Subtype Influenza A Virus and Its EffectIn Vivoon Virus Replication, Tropism, and Transmission

2018 ◽  
Vol 93 (6) ◽  
Author(s):  
Adebimpe O. Obadan ◽  
Jefferson Santos ◽  
Lucas Ferreri ◽  
Andrew J. Thompson ◽  
Silvia Carnaccini ◽  
...  
Keyword(s):  
Public Health ◽  
Amino Acids ◽  
Influenza Virus ◽  
Amino Acid ◽  
Influenza A ◽  
Amino Acid Change ◽  
Single Amino Acid ◽  
Receptor Binding Site ◽  
Single Amino Acid Change

ABSTRACTInfluenza A viruses (IAVs) remain a significant public health threat, causing more than 300,000 hospitalizations in the United States during the 2015–2016 season alone. While only a few IAVs of avian origin have been associated with human infections, the ability of these viruses to cause zoonotic infections further increases the public health risk of influenza. Of these, H9N2 viruses in Asia are of particular importance as they have contributed internal gene segments to other emerging zoonotic IAVs. Notably, recent H9N2 viruses have acquired molecular markers that allow for a transition from avian-like to human-like terminal sialic acid (SA) receptor recognition via a single amino acid change at position 226 (H3 numbering), from glutamine (Q226) to leucine (L226), within the hemagglutinin (HA) receptor-binding site (RBS). We sought to determine the plasticity of amino acid 226 and the biological effects of alternative amino acids on variant viruses. We created a library of viruses with the potential of having any of the 20 amino acids at position 226 on a prototypic H9 HA subtype IAV. We isolated H9 viruses that carried naturally occurring amino acids, variants found in other subtypes, and variants not found in any subtype at position 226. Fitness studies in quails revealed that some natural amino acids conferred anin vivoreplication advantage. This study shows the flexibility of position 226 of the HA of H9 influenza viruses and the resulting effect of single amino acid changes on the phenotype of variantsin vivoandin vitro.IMPORTANCEA single amino acid change at position 226 in the hemagglutinin (HA) from glutamine (Q) to leucine (L) has been shown to play a key role in receptor specificity switching in various influenza virus HA subtypes, including H9. We tested the flexibility of amino acid usage and determined the effects of such changes. The results reveal that amino acids other than L226 and Q226 are well tolerated and that some amino acids allow for the recognition of both avian and human influenza virus receptors in the absence of other changes. Our results can inform better avian influenza virus surveillance efforts as well as contribute to rational vaccine design and improve structural molecular dynamics algorithms.

scholarly journals Single amino acid changes in the mumps virus haemagglutinin–neuraminidase and polymerase proteins are associated with neuroattenuation

2009 ◽  
Vol 90 (7) ◽  
pp. 1741-1747 ◽  
Author(s):  
Tahir H. Malik ◽  
Candie Wolbert ◽  
Laura Nerret ◽  
Christian Sauder ◽  
Steven Rubin
Keyword(s):  
Amino Acid ◽  
Clinical Isolate ◽  
Amino Acid Change ◽  
Mumps Virus ◽  
Site Directed Mutagenesis ◽  
Single Amino Acid ◽  
Supporting Evidence ◽  
L Protein ◽  
Single Amino Acid Change

It has previously been shown that three amino acid changes, one each in the fusion (F; Ala/Thr-91→Thr), haemagglutinin–neuraminidase (HN; Ser-466→Asn) and polymerase (L; Ile-736→Val) proteins, are associated with attenuation of a neurovirulent clinical isolate of mumps virus (88-1961) following serial passage in vitro. Here, using full-length cDNA plasmid clones and site-directed mutagenesis, it was shown that the single amino acid change in the HN protein and to a lesser extent, the change in the L protein, resulted in neuroattenuation, as assessed in rats. The combination of both amino acid changes caused neuroattenuation of the virus to levels previously reported for the clinical isolate following attenuation in vitro. The amino acid change in the F protein, despite having a dramatic effect on protein function in vitro, was previously shown to not be involved in the observed neuroattenuation, highlighting the importance of conducting confirmatory in vivo studies. This report provides additional supporting evidence for the role of the HN protein as a virulence factor and, as far as is known, is the first report to associate an amino acid change in the L protein with mumps virus neuroattenuation.

A single amino acid change makes a rat neuronal sodium channel highly sensitive to pyrethroid insecticides

FEBS Letters ◽  
2000 ◽  
Vol 470 (2) ◽  
pp. 135-138 ◽  
Author(s):  
H. Vais ◽  
S. Atkinson ◽  
N. Eldursi ◽  
A.L. Devonshire ◽  
M.S. Williamson ◽  
...  
Keyword(s):  
Amino Acid ◽  
Sodium Channel ◽  
Amino Acid Change ◽  
Single Amino Acid ◽  
Pyrethroid Insecticides ◽  
Highly Sensitive ◽  
Single Amino Acid Change

Further characterization and determination of the single amino acid change in thetsI138reovirus thermosensitive mutant

2012 ◽  
Vol 58 (5) ◽  
pp. 589-595
Author(s):  
Guy Lemay ◽  
Martin Bisaillon
Keyword(s):  
Amino Acid ◽  
Amino Acid Change ◽  
Genetic Alterations ◽  
Biological Properties ◽  
Single Amino Acid ◽  
Temperature Sensitive ◽  
Nonpermissive Temperature ◽  
Gene Encoding ◽  
Viral Particles ◽  
Single Amino Acid Change

Many temperature-sensitive mutants have been isolated in early studies of mammalian reovirus. However, the biological properties and nature of the genetic alterations remain incompletely explored for most of these mutants. The mutation harbored by the tsI138 mutant was already assigned to the L3 gene encoding the λ1 protein. In the present study, this mutant was further studied as a possible tool to establish the role of the putative λ1 enzymatic activities in viral multiplication. It was observed that synthesis of viral proteins is only marginally reduced, while it was difficult to recover viral particles at the nonpermissive temperature. A single nucleotide substitution resulting in an amino acid change was found; the position of this amino acid is consistent with a probable defect in assembly of the inner capsid at the nonpermissive temperature.

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