What is a helix-turn-helix motif and what are the roles of helix-2 and helix-3 in recognizing DNA?
What will be an ideal response?
Ans: A helix-turn-helix motif is a region of a protein that contains a short ?-helix followed by a turn then another short ?-helix. This motif binds DNA, with one helix fitting in the major groove and the other lying across the groove. Helix 3 recognizes a specific target DNA sequence. Helix 2 forms hydrogen bonds with the phosphate backbone and is necessary for the protein to bind to DNA.
You might also like to view...
In a double-blind test the treating physician knows who is getting the actual treatment
Indicate whether this statement is true or false.
What deficiency symptom is common among plants with inadequate levels of nitrogen, magnesium, iron, zinc, or
copper? What characteristics would be seen in the plants’ leaves?
What will be an ideal response?Development of the pancreas in an embryo into a dual gland that has both exocrine and endocrine functions begins when
A) insulin is produced and bathes stem cells. B) a transcription factor stimulates progenitor cells to give rise to exocrine or endocrine cells. C) a globin gene duplicates and gives rise to alpha and beta globin genes. D) progenitor cells become stem cells.
The compounds involved in phototropism are ____
a. phototropins b. gibberellins c. cytokinins d. phytoestrogens e. statoliths