SV40病毒： SV40病毒染色体有一个约400bp的无核小体区，其 中64bp为复制核心起点。 (1)不完全回文序列（15bp): 核心起点按5'-3方向依次为(2)4个GAGGC反向重复序列； (3)富AT序列。 2025/5/15 16
2025/5/15 16 SV40病毒： SV40病毒染色体有一个约400bp的无核小体区，其 中64bp为复制核心起点。 核心起点按5’-3’方向依次为 (1) 不完全回文序列（15bp)； (2) 4个GAGGC反向重复序列； (3) 富A/T序列
Early palindrome T antigen binding -owm寸CONo寸pPPP888886888588 SGAGTGATSAAGACC44ATSGAGTCASCGGCTCGGCGGGAGCCGSAGACGA4AA8 ICITICC ICGI IGIGIAI GICI 100 % 80 0 60 o 20 10 0 Figure 21.8 Structure of the SV40 ori core.The sequence of the ori core is given just below the numbering of the base pairs in the SV40 DNA. The core extends from base pair 5211 to base pair 31.The positions of the palindrome,the T antigen-binding sites,and the A-T region are given at top.The orientations of the four pentamers in the T antigen-binding site are indicated by arrows.The effects of point mutations in many of the positions are given by the bar graph.The red circles indicate percentage of wild-type replication observed when the indicated base change was made.The open circles at positions 24 and 26 denote effects of A-T changes.(Source:From Deb et al.Molecular and Cellular Biology 6:4582.1986. Copyright 1986 American Society for Microbiology,Washington,DC.Reprinted by permission.)
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SV40:a polyomavirus that is very useful for studying eukaryotic replication enzymes 1500 2000 1000 2500 500 A小 3000 5297 Origin of 0 Replication 5000 35D0 Vviw 4500 4000 SV40启动子位于转录控制区，邻近GC-box和72 op repeat enhancer 2025/5/15 18
2025/5/15 18 SV40: a polyomavirus that is very useful for studying eukaryotic replication enzymes SV40启动子位于转录控制区,邻近GC-box和72bp repeat enhancer
72bp repeat enhancer GC-box Early transcription 而 72b0 72bp HGCHGCHGCHGCHGCHGCHTATA ori Late transcription TATA-box Figure 21.7 Location of the SV40 ori in the transcription control region.The core ori sequence(green)encompasses part of the early region TATA box and the cluster of early transcription initiation sites. Pink arrows denote bidirectional replication away from the replication initiation site.Black arrows denote transcription initiation sites. 2025/5/15 19
2025/5/15 19 TATA-box GC-box 72bp repeat enhancer
3)Features of origins of replication复制起点基本特征： 1. Have several unique,short repeated sequences 它们都是由多个独特的短重复序列组成的。 2.These sequences could be recognized by binding proteins of replication origin这些短重复序列被 多亚基的复制起点结合蛋白识别。 3.Usually there will be an A-T rich sequence near the origins of replication.复制起点附近 一般有一个富AT序列。 对一个生物体基因组而言，复制起点是固定的。 2025/5/15 20
2025/5/15 20 3) Features of origins of replication 复制起点基本特征： 1. Have several unique, short repeated sequences 它们都是由多个独特的短重复序列组成的。 2. These sequences could be recognized by binding proteins of replication origin 这些短重复序列被 多亚基的复制起点结合蛋白识别。 3. Usually there will be an A-T rich sequence near the origins of replication.复制起点附近 一般有一个富AT序列。 对一个生物体基因组而言，复制起点是固定的