Nucleic Acids in Chemistry and Biology
6.6.3.2.3 Complex RNA Polymerase II Promoters. A typical example of a eukaryotic pro- moter that has complex tissue specificity ...
every transcription unit in the chromosome and thus causing transcriptional chaos. This is achieved by use of yet another contro ...
6.6.3.2.6 Chromatin Structure and Gene Expression. Nucleosomesmodulate the accessibility of genes to the transcription machinery ...
but the gene remains expressed. Further more detailed methylation experiments show that methylation of the transcriptional cont ...
base pairing determines the identity of the nucleotide to be added at each step during the replication process. In addition to D ...
to involve the preservation of one of the two parent strands in each of the two newly synthesised duplexes. This is called semi- ...
6.6.4.3 Initiation of DNA Replication. Most of our current knowledge of how DNA replication is initiated comes from prokaryotes. ...
the cycle repeats. The RNA–DNA fragments generated in this way are called Okazaki fragmentsafter their discoverer.^47 The Okazak ...
6.7 DNA Mutation and Genome Repair Every organism is constantly subjected to a barrage of mutagenic agents, including ionising r ...
6.7.2.3 Mismatch Repair. DNA polymerases^54 are extremely accurate at copying DNA templates (10^7 error rate for E. coli) but t ...
double-stranded DNA breaks are repaired by DNA ligase in concert with a multi-subunit complex con- taining DNA protein kinaseand ...
pair. The inference from this is that base pairing is involved during the process. Damage to DNA stimu- lates recombination, sug ...
The first step in the likely mechanism for the generation of the Holliday junction (Figure 6.37) involves formation of a single ...
The Holliday junction is a topologically symmetrical structure. A few simple manipulations of it, which involve no breaking of c ...
6.8.1.2 Some Implications of Recombination. We have already seen that recombination offers advantages to the organism by assorti ...
typically 4–12 nucleotide pairs, but constant for a given transposable element, is duplicated as a result of the insertion. The ...
instance is replicative. Some transposons, including IS1, can use both mechanisms, indicating that these two processes are mecha ...
of its total genome. One of the most interesting and best-studied elements in Drosophilais the P element. This transposable elem ...
truncatedprotein is unable to catalyse transposition and is actually a repressor of the transposase. The mRNA which gives rise t ...
Retrotransposons are the dominant class of transposable element found in eukaryotes. Two types of true retrotransposon are known ...
«
9
10
11
12
13
14
15
16
17
18
»
Free download pdf