In chromosomes, doubly-stranded DNA wraps tightly around histone proteins. Think about the structure of DNA, especially the "backbone," and determine what category of amino acids make up the majority of histones: Histone Octamer tetramer dimer dimer dimer dimer Histone "fastener Here the blue represents histones, and the red is the DNA strand. To help the DNA fold up in an aqueous environment, the histones are nonpolar to exclude water, so many of the amino acid side chains are nonpolar. O The backbone of DNA is the alternating phosphate-sugar part, and the phosphate is negatively charged. Positive charges on the histone residues will bind tightly here, so the acidic amino acids are used here. O The backbone of DNA is the alternating phosphate-deoxyribose part, and the phosphate is negatively charged. Positive charges on the histone residues will bind tightly here, so the basic amino acids are used here. The histones are strongly attracted to the hydrogen-bonding of the base pairs, so the side chains should come from polar (but uncharged) amino acids. tetramer

In chromosomes, doubly-stranded DNA wraps tightly around histone proteins. Think about the structure of DNA, especially the "backbone," and determine what category of amino acids make up the majority of histones: Histone Octamer tetramer dimer dimer dimer dimer Histone "fastener Here the blue represents histones, and the red is the DNA strand. To help the DNA fold up in an aqueous environment, the histones are nonpolar to exclude water, so many of the amino acid side chains are nonpolar. O The backbone of DNA is the alternating phosphate-sugar part, and the phosphate is negatively charged. Positive charges on the histone residues will bind tightly here, so the acidic amino acids are used here. O The backbone of DNA is the alternating phosphate-deoxyribose part, and the phosphate is negatively charged. Positive charges on the histone residues will bind tightly here, so the basic amino acids are used here. The histones are strongly attracted to the hydrogen-bonding of the base pairs, so the side chains should come from polar (but uncharged) amino acids. tetramer

Biochemistry

6th Edition

ISBN:9781305577206

Author:Reginald H. Garrett, Charles M. Grisham

Publisher:Reginald H. Garrett, Charles M. Grisham

Chapter29: Transcription And The Regulation Of Gene Expression

Section: Chapter Questions

Problem 5P

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Similar questions

Describe the d=features of the following DNA-binding domains and how they interact with DNA. Helix-turn-Helix Zinc Finger Leucine Zipper Helix-loop-Helix
Describe the structure of DNA. The two strands of DNA are antiparallel. What does the term antiparallel mean? Describe how DNA is tightly packaged. Your description should include the terms histones, chromatin, nucleosomes and chromosomes.
True or False 1. Histone proteins are able to associate with DNA segments because of the anionic nature of the amino acids arg and lys. 2. DNA molecules can perform their function in replication and transcription as long as the hydrogen bonds between the bases remain intact. 3. A double helix makes one complete turn every 10 residues (3.4nm). Therefore the distance between base pairs is 0.34nm.
A diploid human cell contains approximately 6.4 billion base pairs of DNA. Assuming that the linker DNA encompasses 35 bp, how many nucleosomes are present in such a cell? Use two significant figures. How many histone proteins are complexed with this DNA? use two significant figures.
Histones are proteins found in eukaryotic cell nuclei, tightly bound to DNA, which has many phosphate groups. The pI of histones is very high,about 10.8. What amino acid residues must be present in relatively large numbers in histones? In what way do these residues contribute to the strong binding of histones to DNA?
Description about nucleosome what general type of interaction is(are) largely responsible for the protein-dna associations in a nuclosome? explain
CAN YOU PLEASE ANSWER 1b 1a) The phosphate groups in the sugar-phosphate backbone of each strand of a DNA molecule have a pKa of ~2.14. Normal physiological pH in most cells is 7.0-7.5, which is significantly above the pKa for the phosphate groups, so every phosphate group in the backbone of both strands of a DNA molecule is deprotonated and carries a -1 charge - but DNA in cells is normally double-stranded. Briefly explain, in your own words, why the large negative charges on the backbones of the two strands of a double-stranded DNA molecule don't cause the strands to separate under normal cellular conditions. 1b) If you raise the pH to 12, but keep everything else about the solution in which the double-stranded DNA is dissolved the same, the two strands of DNA will separate/the DNA will denature. Briefly explain, in your own words, why this happens - why does DNA denature at pH 12 but not at pH 7?
Draw the structure of deoxyribose and number the carbon atoms.Describe the numbering of the carbon atoms in deoxyribose withregard to the directionality of a DNA strand. In a DNA doublehelix, what does the term antiparallel mean?
Explain how DNA-binding proteins can make sequence-specific contacts to a double-stranded DNA molecule without breaking the hydrogen bonds that hold the bases together. indicate how, through such contacts, a protein can distinguish a T-A from a C-G pair. indicate the parts of the nucleotide base pairs that could form noncovalent interactions— hydrogen bonds, electrostatic attractions, or hydrophobic interactions -with a DNA-binding protein.
HDAC's are important enzymes involved in the regulation of Gene expression. This is because a. They create the Z form of DNA by removing acetyl groups from cytosines. b. they create euchromatic structure by adding acetyl groups to cytosine. c. they add methyl groups from histones creating less gene expression. d. they remove acetyl groups from histones creating less gene expression. e. they add methyl groups onto cytosines on DNA and create a heterochromatic structure.
5.1) Do you expect DNA strands 1 and 2 below to have the same melting point? Justify your answer. Strand 1: 5′ATTATTTTAAATTTAGCGC3′ Strand 2:5′AAAAAATTTTTTTTTCCGG3′ 5.2) A newly discovered blob protein folds very rapidly in the presence of protein disulphide isomerase and peptidyl prolyl cis-trans isomerase enzymes but aggregates and never folds correctly without protein disulphide isomerase. Explain why this might occur.
Single-stranded binding proteins (SSBPs) bind to single-stranded DNA at the replication fork and prevent formation of short hairpin sequences that would otherwise impede DNA synthesis. What sorts of sequences in single-stranded DNA might be able to form a hairpin? Write out an example of a sequence that could form a 5-nucleotide hairpin loop, and draw it.