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Hepatitis B Virus PRE Alpha
The Hepatitis B virus PRE stem-loop alpha (HBV PRE SL alpha) is an RNA structure that is shown to play a role in nuclear export of HBV mRNAs. HBV PREalpha consists of a 30 nt stem-loop, with a 5 nt apical loop. The conserved stem-loop was predicted within the HBV PRE sequence and confirmed by mutagenesis. The exact role of this structure in nuclear export has not yet been determined. See also * Hepatitis B virus PRE beta *HBV RNA encapsidation signal epsilon The HBV RNA encapsidation signal epsilonHBV_epsilon is an element essential for Hepatitis B virus, HBV virus replication. It is an RNA structure situated near the 5' end of the Hepatitis B virus, HBV pregenomic RNA. The structure consists of a l ... * Hepatitis_B virus PRE 1151–1410 References Cis-regulatory RNA elements Hepatitis B virus {{molecular-cell-biology-stub ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
RNA Structure
Nucleic acid structure refers to the structure of nucleic acids such as DNA and RNA. Chemically speaking, DNA and RNA are very similar. Nucleic acid structure is often divided into four different levels: primary, secondary, tertiary, and quaternary. Primary structure Primary structure consists of a linear sequence of nucleotides that are linked together by phosphodiester bond. It is this linear sequence of nucleotides that make up the primary structure of DNA or RNA. Nucleotides consist of 3 components: # Nitrogenous base ## Adenine ## Guanine ## Cytosine ## Thymine (present in DNA only) ## Uracil (present in RNA only) # 5-carbon sugar which is called deoxyribose (found in DNA) and ribose (found in RNA). # One or more phosphate groups. The nitrogen bases adenine and guanine are purine in structure and form a glycosidic bond between their 9 nitrogen and the 1' -OH group of the deoxyribose. Cytosine, thymine, and uracil are pyrimidines, hence the glycosidic bonds form betwe ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Hepatitis B Virus
''Hepatitis B virus'' (HBV) is a partially double-stranded DNA virus, a species of the genus '' Orthohepadnavirus'' and a member of the '' Hepadnaviridae'' family of viruses. This virus causes the disease hepatitis B. Disease Despite there being a vaccine to prevent Hepatitis B, HBV remains a global health problem. Hepatitis B can be acute and later become chronic, leading to other diseases and health conditions. In addition to causing hepatitis, infection with HBV can lead to cirrhosis and hepatocellular carcinoma. It has also been suggested that it may increase the risk of pancreatic cancer. Roles in disease Viral infection by ''Hepatitis B virus'' (HBV) causes many hepatocyte changes due to the direct action of a protein encoded by the virus, HBx, and to indirect changes due to a large increase in intracellular reactive oxygen species (ROS) after infection. HBx appears to dysregulate a number of cellular pathways. HBx causes dysregulation in part by binding to genomic ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Nucleotide
Nucleotides are organic molecules consisting of a nucleoside and a phosphate. They serve as monomeric units of the nucleic acid polymers – deoxyribonucleic acid (DNA) and ribonucleic acid (RNA), both of which are essential biomolecules within all life-forms on Earth. Nucleotides are obtained in the diet and are also synthesized from common nutrients by the liver. Nucleotides are composed of three subunit molecules: a nucleobase, a five-carbon sugar ( ribose or deoxyribose), and a phosphate group consisting of one to three phosphates. The four nucleobases in DNA are guanine, adenine, cytosine and thymine; in RNA, uracil is used in place of thymine. Nucleotides also play a central role in metabolism at a fundamental, cellular level. They provide chemical energy—in the form of the nucleoside triphosphates, adenosine triphosphate (ATP), guanosine triphosphate (GTP), cytidine triphosphate (CTP) and uridine triphosphate (UTP)—throughout the cell for the many c ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Stem-loop
Stem-loop intramolecular base pairing is a pattern that can occur in single-stranded RNA. The structure is also known as a hairpin or hairpin loop. It occurs when two regions of the same strand, usually complementary in nucleotide sequence when read in opposite directions, base-pair to form a double helix that ends in an unpaired loop. The resulting structure is a key building block of many RNA secondary structures. As an important secondary structure of RNA, it can direct RNA folding, protect structural stability for messenger RNA (mRNA), provide recognition sites for RNA binding proteins, and serve as a substrate for enzymatic reactions. Formation and stability The formation of a stem-loop structure is dependent on the stability of the resulting helix and loop regions. The first prerequisite is the presence of a sequence that can fold back on itself to form a paired double helix. The stability of this helix is determined by its length, the number of mismatches or bulges i ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Mutagenesis
Mutagenesis () is a process by which the genetic information of an organism is changed by the production of a mutation. It may occur spontaneously in nature, or as a result of exposure to mutagens. It can also be achieved experimentally using laboratory procedures. A mutagen is a mutation-causing agent, be it chemical or physical, which results in an increased rate of mutations in an organism's genetic code. In nature mutagenesis can lead to cancer and various heritable diseases, and it is also a driving force of evolution. Mutagenesis as a science was developed based on work done by Hermann Muller, Charlotte Auerbach and J. M. Robson in the first half of the 20th century. History DNA may be modified, either naturally or artificially, by a number of physical, chemical and biological agents, resulting in mutations. Hermann Muller found that "high temperatures" have the ability to mutate genes in the early 1920s, and in 1927, demonstrated a causal link to mutation upon exper ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Hepatitis B Virus PRE Beta
The Hepatitis B virus PRE stem-loop beta (HBV PRE SL-beta) is an RNA structure that is shown to play a role in nuclear export of HBV mRNAs. The minimal HBV PREbeta structure consists of a 23 nt stem-loop, with a 9 nt apical loop. The conserved stem-loop was predicted within the HBV PRE sequence and confirmed by mutagenesis. See also * Hepatitis B virus PRE alpha *HBV RNA encapsidation signal epsilon The HBV RNA encapsidation signal epsilonHBV_epsilon is an element essential for Hepatitis B virus, HBV virus replication. It is an RNA structure situated near the 5' end of the Hepatitis B virus, HBV pregenomic RNA. The structure consists of a l ... * Hepatitis B virus PRE 1151–1410 References Cis-regulatory RNA elements Hepatitis B virus {{molecular-cell-biology-stub ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
HBV RNA Encapsidation Signal Epsilon
The HBV RNA encapsidation signal epsilonHBV_epsilon is an element essential for HBV virus replication. It is an RNA structure situated near the 5' end of the HBV pregenomic RNA. The structure consists of a lower stem, a bulge region, an upper stem and a tri-loop. The structure was determined and refined through enzymatic probing and NMR spectroscopy. The closure of the tri-loop was not predicted by RNA structure prediction programs but observed in the NMR structure. The regions shown to be critical for encapsidation of the RNA in the viral lifecycle are the bulge, upper stem and tri-loop which interact with the terminal protein domain of the HBV viral polymerase. See also *Heron HBV RNA encapsidation signal epsilon The Avian HBV RNA encapsidation signal epsilon (AHBV epsilon) is an RNA structure that is shown to facilitate encapsidation of the pregenomic RNA required for viral replication. There are two main classes of encapsidation signals in avian he ... * Duck HB ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Hepatitis B Virus PRE 1151–1410
Hepatitis B virus PRE 1151–1410 (HBV post-transcriptional regulatory element, nucleotides 1151–1410) is a part of 500 base pair long HBV PRE, that has been proposed to be the hepatitis B virus (HBV) RNA export element. However, the function is controversial and new regulatory elements have been predicted within PRE. PRE 1151–1410 enhances nuclear export of intronless transcripts and represses the splicing mechanism to a comparable degree to that of the full-length PRE. Hence it was proposed to be the core HBV PRE element. PRE1151–1410 contains 3 known regulatory elements: PRE SL-alpha (nucleotides 1292–1321), human La protein binding site (nucleotide 1275–1291), SRE-1 (nucleotides 1252–1348). See also * HBV PRE SL alpha * HBV PRE SL beta * HBV RNA encapsidation signal epsilon The HBV RNA encapsidation signal epsilonHBV_epsilon is an element essential for HBV virus replication. It is an RNA structure situated near the 5' end of the HBV pregenomic RNA. The ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Cis-regulatory RNA Elements
''Cis-acting replication elements'' bring together the 5′ and 3′ ends during replication of positive-sense single-stranded RNA viruses (for example Picornavirus, Flavivirus, coronavirus, togaviruses, Hepatitis C virus) and double-stranded RNA viruses (for example rotavirus and reovirus). See also *Cis-regulatory element * List of cis-regulatory RNA elements * Enterovirus cis-acting replication element and Enterovirus 5′ cloverleaf cis-acting replication element *Cardiovirus cis-acting replication element (CRE) * Coronavirus SL-III cis-acting replication element (CRE) * Rotavirus cis-acting replication element * Hepatitis C virus cis-acting replication element * Flavivirus 3′ UTR cis-acting replication element (CRE) *Potato virus X cis-acting regulatory element The Potato virus X cis-acting regulatory element is a cis-acting regulatory element found in the 3' UTR of the Potato virus X genome. This element has been found to be required for minus strand RNA accumulation an ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
