9. (1pt) Many DNA binding proteins initially make contact with DNA non-specifica

Question

9. (1pt) Many DNA binding proteins initially make contact with DNA non-specifically and then scan the DNA for their target nucleotide sequence producing specific contacts in the major groove of DNA. Non-specific contacts are usually through salt bridge formation between amino acids in the transcription factor and the phosphate backbone. Which of the following amino acids is most likely to form such a salt bridge a. Thr b. Val Glu e. Asn 10. (1pts) Sequence-specific contact with DNA occurs largely through which of the following protein structures (use CAP as an example)? a. -helix -pleated sheet c. -barrel d. Immunoglobulin motif e. Flexible loop structures 11. (1pts) The CAP homodimer (with bound cAMP) binds a 22-base-pair DNA consensus sequence with a two-fold axis of symmetry. CAP can be seen to induce a sharp bend of 90 in target DNA. Each CAP monomer has numerous contacts with its DNA half site. The C-terminal domain of each CAP monomer contains a helix-turn-helix (H-T-H) DNA-binding motif found in most bacterial transcription factors. This motif is found, in a modified form (the homeodomain), in some eukaryotic transcription factors as well. The H-T-H motif confers DNA- binding specificity. Which of the following sets of amino acids are located on the recognition helix (green) of CAP and bind to the bases lining the DNA major groove? DNA half site a. Arg GluArg b. Val39 Lys26 c. Asn268 Gly 6 Lys d. Glu"2, Ser3, Thr7 ean

Explanation / Answer

1. option d is correct.

glutamate and aspartic acid or aspartate shows Hai tendency of formation of salt bridges.

here aspartic acid or aspartate not given so the glutamate is correct answer.

2. option A is correct.

helix structures shows high capacity of interaction with DNA.

in the DNA binding proteins the number of helices are more as compared to other secondary structures.

According to check guidelines you have toyou have to upload each questions separately.

I answered the questions as time permitted me.

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