What are the major differences between LTR and non-LTR retrotransposons?
LTR retrotransposons move by first being transcribed into RNA, followed by reverse transcription leading to a DNA copy that recombines with genomic DNA. Non-LTR retrotransposons move through a somewhat different RNA-mediated event, discussed below (Eickbush and Malik, 2002).
What is LTR in genes?
A long terminal repeat (LTR) is a pair of identical sequences of DNA, several hundred base pairs long, which occur in eukaryotic genomes on either end of a series of genes or pseudogenes that form a retrotransposon or an endogenous retrovirus or a retroviral provirus.
What distinguishes a retrovirus from an LTR transposon?
Retroviruses and long terminal repeat (LTR) retrotransposons share a common structural organization. The main difference between these retroelements is the presence of a functional envelope (env) gene in retroviruses, which is absent or nonfunctional in LTR retrotransposons.
Is ALU a retrotransposon?
Alu elements are highly repetitive DNA sequences that can be classified as SINEs (short interspersed elements), which are themselves a type of “nonautonomous” retrotransposon.
What is the difference between SINEs and LINEs?
The key difference between LINEs and SINEs is that LINEs (long interspersed nuclear elements) are a type of longer non-LTR retrotransposons while SINEs (short interspersed nuclear elements) are a type of much shorter non-LTR retrotransposons. Non-LTR retrotransposons do not contain long terminal repeats (LTR).
What does Gag Pol do?
Incorporation of Gag-Pol or its mature products into virions is required for infectivity, as they mediate the synthesis and integration of viral cDNA in infected cells (46). In addition, cleavage of the precursor proteins by PR is required for morphological maturation of the virion core (15, 23, 24).
What is a Pol gene?
Pol (DNA polymerase) refers to a gene in retroviruses, or the protein produced by that gene.
Is LTR autonomous?
The LTRs are the direct sequence repeats that flank the internal coding region, which – in all autonomous (functional) LTR retrotransposons – includes genes encoding both structural and enzymatic proteins.
What is LTR in virology?
flanking nucleotide sequences, known as long terminal repeats (LTR), which code for double-stranded DNA that can recognize host cell DNA sequences for integration of the proviral DNA into the host cell chromosome.