IV Mutation Detail Information

Virus Mutation IV Mutation R294K


Basic Characteristics of Mutations
Mutation Site R294K
Mutation Site Sentence NAs from these two viruses are distinct as the A/Shanghai/1/2013 NA has an R294K substitution that can confer NA inhibitor oseltamivir resistance.
Mutation Level Amino acid level
Mutation Type Nonsynonymous substitution
Gene/Protein/Region NA
Standardized Encoding Gene NA
Genotype/Subtype H7N9
Viral Reference -
Functional Impact and Mechanisms
Disease Influenza A    
Immune -
Target Gene -
Clinical and Epidemiological Correlations
Clinical Information -
Treatment oseltamivir
Location China
Literature Information
PMID 24165891
Title Characterization of two distinct neuraminidases from avian-origin human-infecting H7N9 influenza viruses
Author Wu Y,Bi Y,Vavricka CJ,Sun X,Zhang Y,Gao F,Zhao M,Xiao H,Qin C,He J,Liu W,Yan J,Qi J,Gao GF
Journal Cell research
Journal Info 2013 Dec;23(12):1347-55
Abstract An epidemic of an avian-origin H7N9 influenza virus has recently emerged in China, infecting 134 patients of which 45 have died. This is the first time that an influenza virus harboring an N9 serotype neuraminidase (NA) has been known to infect humans. H7N9 viruses are divergent and at least two distinct NAs and hemagglutinins (HAs) have been found, respectively, from clinical isolates. The prototypes of these viruses are A/Anhui/1/2013 and A/Shanghai/1/2013. NAs from these two viruses are distinct as the A/Shanghai/1/2013 NA has an R294K substitution that can confer NA inhibitor oseltamivir resistance. Oseltamivir is by far the most commonly used anti-influenza drug due to its potency and high bioavailability. In this study, we show that an R294K substitution results in multidrug resistance with extreme oseltamivir resistance (over 100 000-fold) using protein- and virus-based assays. To determine the molecular basis for the inhibitor resistance, we solved high-resolution crystal structures of NAs from A/Anhui/1/2013 N9 (R294-containing) and A/Shanghai/1/2013 N9 (K294-containing). R294K substitution results in an unfavorable E276 conformation for oseltamivir binding, and consequently loss of inhibitor carboxylate interactions, which compromises the binding of all classical NA ligands/inhibitors. Moreover, we found that R294K substitution results in reduced NA catalytic efficiency along with lower viral fitness. This helps to explain why K294 has predominantly been found in clinical cases of H7N9 infection under the selective pressure of oseltamivir treatment and not in the dominant human-infecting viruses. This implies that oseltamivir can still be efficiently used in the treatment of H7N9 infections.
Sequence Data -
Mutation Information
Note
Basic Characteristics of Mutations
  • Mutation Site: The specific location in a gene or protein sequence where a change occurs.
  • Mutation Level: The level at which a mutation occurs, including the nucleotide or amino acid level.
  • Mutation Type: The nature of the mutation, such as missense mutation, nonsense mutation, synonymous mutation, etc.
  • Gene/Protein/Region: Refers to the specific region of the virus where the mutation occurs. Including viral genes, viral proteins, or a specific viral genome region. If the article does not specifically indicate the relationship between the mutation and its correspondence, the main
  • Gene/Protein/Region studied in the article is marked.
  • Genotype/Subtype: Refers to the viral genotype or subtype where the mutation occurs. If the article does not specifically indicate the relationship between the mutation and its correspondence, the main Genotype/Subtype studied in the article is marked.
  • Viral Reference: Refers to the standard virus strain used to compare and analyze viral sequences.
Functional Impact and Mechanisms
  • Disease: An abnormal physiological state with specific symptoms and signs caused by viral infection.
  • Immune: The article focuses on the study of mutations and immune.
  • Target Gene: Host genes that viral mutations may affect.
Clinical and Epidemiological Correlations
  • Clinical Information: The study is a clinical or epidemiological study and provides basic information about the population.
  • Treatment: The study mentioned a certain treatment method, such as drug resistance caused by mutations. If the study does not specifically indicate the relationship between mutations and their correspondence treatment, the main treatment studied in the article is marked.
  • Location: The source of the research data.
Literature Information
  • Sequence Data: The study provides the data accession number.