HBV Mutation Detail Information

Virus Mutation HBV Mutation T1753C


Basic Characteristics of Mutations
Mutation Site T1753C
Mutation Site Sentence Clone 4B harbored T1753C/A1762T/G1764A/C1766T quadruple mutation in the core promoter. To directly test the contribution of core promoter mutations, point mutations found in clone 4B were introduced stepwise into the low replicating clone 2A.
Mutation Level Nucleotide level
Mutation Type Nonsynonymous substitution
Gene/Protein/Region Core Promoter
Standardized Encoding Gene
Genotype/Subtype -
Viral Reference -
Functional Impact and Mechanisms
Disease Hepatitis B, Chronic    
Immune -
Target Gene -
Clinical and Epidemiological Correlations
Clinical Information -
Treatment -
Location -
Literature Information
PMID 17627632
Title Impact of viral genotypes and naturally occurring mutations on biological properties of hepatitis B virus
Author Tong S
Journal Hepatology research : the official journal of the Japan Society of Hepatology
Journal Info 2007 Jul;37(s1):S3-8
Abstract Hepatitis B patients worldwide are infected with different viral genotypes. Within the same individual the dominant viral species evolves over the course of chronic infection to generate viral variants or mutants. The mutations, often selected by the host immune response or antiviral therapy, are sometimes restricted by viral genotypes. We are interested in characterizing mutations that affect the expression of hepatitis B e-antigen (HBeAg), a protein with a large effect on duration of infection and severity of liver diseases. HBeAg is encoded by the precore region in addition to the core gene. Core promoter mutations reduce HBeAg expression at the transcriptional level. We found that the hot spot mutations (A1762T/G1764A) only mildly reduced HBeAg expression and enhanced genome replication, while incorporation of additional core promoter mutations intensified both phenotypes. At the step of translation, a G1896A nonsense mutation in the precore region abolishes HBeAg expression. We first reportedthat the G1896A mutation rarely occurred in genotype A. Subsequent studies by others established the role of polymorphism at nucleotide 1858, rather than genotype, as the determinant for the G1896A mutation. Conversion of the precore/core protein to HBeAg requires proteolytic removal of both the amino and carboxy termini, and a (151)RRGR(154) motif has been implicated as the carboxy terminal cleavage site. In this regard, genotype A is unique in possessing a dipeptide insertion that expands the motif into (151)RRDRGR(156). We found that genotype A is cleaved primarily at R156, generating a mature HBeAg that is two amino acids longer than HBeAg from other genotypes. There are different avenues whereby HBeAg expression or its antigenicity can be modulated by viral genotype and naturally occurring mutations.
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.