Question

In: Chemistry

Does the crystal stucture of xanthine dehydrogenase exhibit quaternary structure? If yes, how many subunits do...

Does the crystal stucture of xanthine dehydrogenase exhibit quaternary structure? If yes, how many subunits do you recognize (what are they)?

Solutions

Expert Solution

Answer :-   Xanthine dehydrogenase/oxidase (XDH1/XO) is a complex metallo-flavoprotein catalyzing the oxidative hydroxylation of purines, pyrimidines, pterines, and aldehyde substrates using NAD+ or molecular oxygen as electron acceptor. Mammalian XDH (EC 1.1.1.204) is a homodimer (290 kDa), with each subunit containing a single molybdenum cofactor (Moco) as well as two iron-sulfur clusters and an FAD molecule.

The enzyme is encoded by two genes, xdhA and xdhB, with the FeS clusters and FAD bound to the XDHA subunit and Moco bound to the XDHB subunit. A third protein, designated XDHC, was shown to be essential for XDH activity in R. capsulatus but was not found to be a subunit of active XDH (7).

The XDHB subunit it is cleaved into four fragments with molecular weights of 35,000, 30,000, 20,000 and 15,000, whereas the XDHA subunit remains unchanged. However, the quaternary structure and the activity of the enzyme remain unaltered, showing no increase in the activity with molecular oxygen as electron acceptor (data not shown).


Related Solutions

What starts a dislocation and how does this advance in a crystal structure?
What starts a dislocation and how does this advance in a crystal structure?
1. How does the quaternary structure of hemoglobin influence its more efficient offloading of O2 in...
1. How does the quaternary structure of hemoglobin influence its more efficient offloading of O2 in tissues compared to myoglobin? 2. How does the Kd of hemoglobin for O2 change in the increasingly lower pH environment of actively fermenting muscles during a sprint? 3. If muscles ferment glucose to lactate during a sprint, what biochemical process ultimately uses that lactate to produce new glucose and in what tissue is it active?
What is translation, where does it occur? How many ribosomal subunits are there, and where are...
What is translation, where does it occur? How many ribosomal subunits are there, and where are they constructed? What are the P and A sites? What occurs during initiation, elongation, and termination and what are the three steps of elongation. What is the function of the stop codon?
Can someone explain the role of the three subunits of the pyruvate dehydrogenase complex? Like how...
Can someone explain the role of the three subunits of the pyruvate dehydrogenase complex? Like how those subunits help with the complex turnign pyruvate into acetyl coA? Also why and how does the pyruvate move from cytoplasm to mitochondria? Also why does the Krebs cycle not accept pyruvate? Why does it need to be turned into acetyl coA first?
Describe how the different enzyme subunits of pyruvate dehydrogenase interact with their cofactors to catalyze decarboxylation...
Describe how the different enzyme subunits of pyruvate dehydrogenase interact with their cofactors to catalyze decarboxylation of pyruvate.
How does the crystal structure influence friction? Why do FCC metals have more friction than HCP...
How does the crystal structure influence friction? Why do FCC metals have more friction than HCP metals?
Many linear polymers can exhibit large amounts of deformation. Explain how the structure of this type...
Many linear polymers can exhibit large amounts of deformation. Explain how the structure of this type of polymer changes as it undergoes loading to failure. The type of polymer is linear. How do linear polymers change under loading?
does HIV have a protein coat? if yes what is its structure? what enzymes does it...
does HIV have a protein coat? if yes what is its structure? what enzymes does it use for its metabolism?
how does x-rays interact with atom in a crystal?
how does x-rays interact with atom in a crystal?
BIO&160 QUESTIONS: 3. Explain how the various levels of structure of proteins (primary, secondary, tertiary, quaternary)...
BIO&160 QUESTIONS: 3. Explain how the various levels of structure of proteins (primary, secondary, tertiary, quaternary) are responsible for protein's very important role as enzymes. In your answer, use the following terms correctly - induced fit, substrate, active site.
ADVERTISEMENT
ADVERTISEMENT
ADVERTISEMENT