Concept explainers
Even though actinobacteria are high G + C organisms, there are regions of the genome that are AT-rich. Suggest a few such regions and explain why they must be more AT-rich.
Actinobacteria are otherwise known as Actinomycetes are Gram positive in nature. These bacteria are terrestrial as well as aquatic in nature. These microbes are chemoorganotrophs. These bacteria produce metabolites that are used as antibiotics, antihelminthic and anticancer drugs in patients who have undergone organ transplantation.
Explanation of Solution
The origin of replication or oriC, at which the DnaA protein binds are rich in AT (adenine-thymine) that assists in the formation of replication fork. This process is known as melting. This is because the AT rich region is more flexible as well as easier to unwind as they are linked by two hydrogen bonds. These regions also exist in certain parts of the genome. In a similar way, the promoter regions where the enzyme, RNA polymerase binds should be AT-rich for the formation of open complexes in ease to initiate the process of transcription. The AT regions will allow for necessary bending as well as proper gene regulation.
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Chapter 24 Solutions
Prescott's Microbiology
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