Question

How do regulatory proteins interact with DNA?

Answer 1

Hint: Regulatory proteins or transcription factors regulate transcription. These proteins bind to regulatory element or promoter regions of DNA, which are found near promoters.

Complete answer:
The use of a gene to make a protein is called gene expression. It includes the synthesis of the protein by DNA transcription processes and the translation of mRNA. It may also involve further processing of the protein after synthesis. Gene expression is controlled to ensure that the right proteins are generated at the right time and in the right place.

A good example of this is the lac operon in prokaryotic DNA that dictates whether bacteria in the lower GI are using lactose or glucose for energy.

The lacI area of DNA constitutively expresses a repressor molecule that negatively controls lacZ and lacY expression by blocking RNA raw materials from RNA synthesising in order to break down galactose.

When there is a high level of extracellular glucose, the galactoside permease inhibits the cell membrane from being permeable to lactose.

However, when extracellular glucose levels are low, the cell membrane may be more permeable to lactose, which causes the transcription of lacY and lacZ genes to be expressed in proteins and enzymes that promote the metabolism of lactose.

In addition, when the cAMP-CAP complex is formed within the cell as a result of intercellular lactose, it promotes the transcription of the genes mentioned above.

Regulation of gene expression is extremely important in the early development of the organism. Regulatory proteins must activate certain genes in particular cells at just the right time so that the individual develops normal organs and organ systems. Homeobox genes are a large group of genes that regulate development at the embryonic stage. There are an estimated 235 functional homs in humans.

An estimated 235 functional homeobox genes are present in humans. They are present on every chromosome and are generally grouped into clusters. Homeobox genes contain instructions for making 60 amino acid chains called homeodomains. Homeodomain-containing proteins are transcription factors that bind and control the activities of other genes. The homeodomain is a part of the protein that binds to it.

Note: Some types of cancer are caused by mutations in genes that control the cell cycle. Cancer-causing mutations most commonly occur in two types of regulatory genes, called tumour suppressor genes and proto-oncogenes.