Chapter 16 Retroviruses And retroposons 莘大
Chapter 16 Retroviruses And retroposons
16.1 Introduction 16.2 The retrovirus life cycle involves transposition-like events 16. 3 Retroviral genes codes for polyproteins 16.4 Viral dna is generated by reverse transcription 16.5 Viral dna integrates into the chromosome 16.6 Retroviruses may transduce cellular sequences 16. 7 Yeast Ty elements resemble retroviruses 16. 8 Many transposable elements reside in D. melanogaster 16.9 Retroposons fall into two classes 16. 10 The Alu family has many widely dispersed members 消当
16.1 Introduction 16.2 The retrovirus life cycle involves transposition-like events 16.3 Retroviral genes codes for polyproteins 16.4 Viral DNA is generated by reverse transcription 16.5 Viral DNA integrates into the chromosome 16.6 Retroviruses may transduce cellular sequences 16.7 Yeast Ty elements resemble retroviruses 16.8 Many transposable elements reside in D. melanogaster 16.9 Retroposons fall into two classes 16.10 The Alu family has many widely dispersed members
16.1 Introduction Retroposon is a transposon that mobilizes via an rna form the dna element is transcribed into rna. and then reverse transcribed into dna. which is inserted at a new site in the genome 消当
Retroposon is a transposon that mobilizes via an RNA form; the DNA element is transcribed into RNA, and then reversetranscribed into DNA, which is inserted at a new site in the genome. 16.1 Introduction
■■■■■国■国■ 9.1 Introduction ■■■■■■■■■■ RNA Figure 16. 1 The reproductive Provins cycles of retroviruses and retroposons involve △ alternation of reverse transcription from rNa to FRNA DNA With transcription from ■■■■■■■■■ DNA to RNA. only NTRACELLULAR■ retroviruses can generate infectious particles EXTRACELLULAR Retroposons are confined ■■■■■■■■■■ an intracellular cycle 消当 Retrovirus
Figure 16.1 The reproductive cycles of retroviruses and retroposons involve alternation of reverse transcription from RNA to DNA with transcription from DNA to RNA. Only retroviruses can generate infectious particles. Retroposons are confined to an intracellular cycle. 9.1 Introduction
16.2 The retrovirus life cycle involves transposition like events LTR is an abbreviation for long-terminal repeat 消当
LTR is an abbreviation for long-terminal repeat. 16.2 The retrovirus life cycle involves transposition like events
16.2 The retrovirus RNA life cycle involves Reverse transcripti transposition like LTR LTR Linear DNA M events Figure 16.2 The retroviral Integration Circul arization life cycle proceeds by reverse transcribing the RNA genome into duplex DNA, which is inserted Provirus VA into the host genome, in Transcription order to be transcribed into rna RNA 消当
Figure 16.2 The retroviral life cycle proceeds by reverse transcribing the RNA genome into duplex DNA, which is inserted into the host genome, in order to be transcribed into RNA. 16.2 The retrovirus life cycle involves transposition like events
16.2 The retrovirus life cycle involves transposition like events 170-1260 viral genome 2000 2900 1800 Translation F Splicing Translation genomic RNA Processing i Processing Each gene generates several protein products NC nucleocapsid (pack aging er of rna Processin IN integrase(integrates provir us DNA int Figure 16. 3 The genes of the retrovirus are expressed as polyproteins that are processed into individual products 请莘大
Figure 16.3 The genes of the retrovirus are expressed as polyproteins that are processed into individual products. 16.2 The retrovirus life cycle involves transposition like events
16.2 The retrovirus life cycle involves transposition like events Budding initiates Virus released Figure 16.4 Retroviruses(HIv) bud from the plasma a01 um mem brane of an Bud elongates 4 virus matures infected cell Photograph kindly provided by Matthew gonda 消当
Figure 16.4 Retroviruses (HIV) bud from the plasma membrane of an infected cell. Photograph kindly provided by Matthew Gonda. 16.2 The retrovirus life cycle involves transposition like events
16.2 The retrovirus life cycle involves transposition like events RNA form of y irus Figure 16.5 ant l13 0-8 Retroviral rna ∠80-100~2000 2900~1800 7n12 ends in direct Linear DNA form of virus repeats(R), the U3RUs gag por env U3 R free linear dna ends in ltrs LTR 250-1400b and the provirus Integrated dNA form of virus ends in ltrs U3 has lost 2 bp U5 has lost 2 bp that are shortened by Host U3 RU5 gag poy eny U3 RU5, Host two bases each 4-6 bp repeat of 4-6 bp repeat of 消当 target dnA target DNA
Figure 16.5 Retroviral RNA ends in direct repeats (R), the free linear DNA ends in LTRs, and the provirus ends in LTRs that are shortened by two bases each. 16.2 The retrovirus life cycle involves transposition like events
Retrovirus provides plus strand RNA U3 R Prmer tRNA anneals to binding site on retro 16.2 The retrovirus Reverse transcriptase life cvcle involves starts synthesis of minus strand DNA Minus stran 嘉↓ transposition like events Enzymes reaches end of template strand, generating strong stop minus dNa Strong stop minus Figure 16.6 Minus strand 5 terminal region of RNA strand is degrade dNA iS generated by switching templates during ow eno reverse transcription e-stranded DNA R region pairs with inus in first jump to another paint iral rNa muuu Reverse transcriptase 消当 31
Figure 16.6 Minus strand DNA is generated by switching templates during reverse transcription. 16.2 The retrovirus life cycle involves transposition like events
