3.RNase P是一种 ，含有 作为它的活性部位，这种酶在 序列的 切割 。
4. 写出两种合成后不被切割或拼接的RNA： 和 。
5. The regions of DNA in a eukaryotic gene that encode a polypeptide product are called .
6. During the first step in mRNA splicing, the hydroxyl group in the _______ position of the branch point nucleotide attacks the phosphate bond 5’ of the _______ (nucleotide) located at the 5’ end of the intron, thereby forming a ____ structure.
7. During type 2 mRNA capping, GTP is added to the first nucleotide of an mRNA via a 5’-5’ __________ linkage, and _______ groups donated by S-adenosyl methionine are added to the 7’ position of the guanine cap and the 2’ position of the first _____ (number) nucleotides of the mRNA.
8. What is the intermediate form in RNA processing?
9. Besides base pairing with the pre-mRNA, U6 base-pairs with two snRNAs, What are they?
10. What is added to the 5'-end of many eukaryotic mRNAs after transcription?
四、问答题：
1. Why do pre-mRNAs get smaller during RNA processing?
2. In cartoon form, draw the three fundamental steps in splicing out an intron of mRNA with two exons separated by one intron (you don’t need to include any proteins). (a)Label chemical polarity of the mRNA at each step, (b)clearly mark the exon/intron boundaries, and (c)show the starting structure, (d)the intermediate structure and (e)the two end-products of the splicing reaction specifically labeling the (f)lariat structure and the (g)branch point. Be as specific as possible.
3. List the order in which U RNAs are added to an intron during splicing and where they bind.
4. Illustrate the main difference between group II splicing and nuclear splicing.
5. Diagram the process of splicing human pre-tRNA.
6. Draw a diagram of the polyadenylation process, beginning with an RNA that is being elongated past the polyadenylation site.
7. Describe what we mean by RNA editing. Draw a diagram of a model of RNA editing.
8.论述真核生物mRNA前体转录后3'末端剪切和polyA加工过程。
9.简述CTD磷酸化与转录的关系。
10.回答下列有关核内mRNA剪接的问题: (1) 特殊的中间产物是什么? (2) 有几个特殊序列? (3) 分支点上磷酸二酯键的性质。 (4) U2, U4和U6 snRNA之间在剪接中的相应关系。
11.正常的人类肝细胞中制备的RNA进行琼脂糖电泳后，与一个长为200bp的LDL受体基因外显子2标记探针进行Northern blot杂交，杂交结果出现一条长为4.5kb的标记带,与经过适当酶切的基因组DNA(采用的酶在LDL受体基因两侧有两个酶切位点)进行Southern blot杂交,则出现的标记带其分子量为50kb. 若将一患者的肝细胞中制备的RNA进行琼脂糖电泳后，与相同的探针进行Northern blot杂交，杂交结果出现一条长为20kb的标记带,与经过适当酶切的基因组DNA(采用的酶在LDL受体基因两侧有两个酶切位点)进行Southern blot杂交,则出现的标记带其分子量一样为50kb,请解释之。
习题十
一、名词解释：
SD sequence，the wobble hypothesis，polysome，IF，EF，RF,ORFs,
二、选择题：
1. Which of the following eukaryotic initiation factors is NOT correctly paired with its function?（ ）
a). eIF-2 binds tRNAiMet to the ribosomal subunit
b). eIF-6 is an anti-association factor
c). eIF-4F is composed of three subunits, one of which is a RNA helicase
d). eIF-5 stimulates 50S subunit binding to the 30S pre-initiation complex
e). none of the above
2. During translation in E. coli, charged tRNAs bind and interact with（ ）
a). only the 50S subunit;
b) the P site;
c). the A site;
d). the E site;
e). all of the above.
3. Which of the following is NOT a feature of eukaryotic gene expression? （ ）
a). polycistronic mRNAs are very rare ;
b) many genes are interrupted by non-coding DNA sequences
