Other nucleic acid functions

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Other nucleic acid functions
2014-03-11 11:05:13
MCDB chapter
Chapter 9
Chapter 9
Show Answers:

  1. What are some "other" functions of nucleic acid?
    • Chemical energy sources
    • Electron carriers
    • Regulatory molecules
    • Cofactors
  2. Chemical energy sources:
    Chemical energy sources: phosphate covalently linked to the 5’ hydroxyl of a ribonucleotide.
  3. Electron carriers:
    Electron carriers: NAD+, the N+ can pick up and drop off two electrons(N+ hydride is unstable with one electron). FAD, has two N to carry electrons and the molecule can pick up one or two electrons (very stable due to resonance). Both FAD and NAD+ have identical lower portion, but their upper portions are not.
  4. Regulatory molecules:
    Regulatory molecules: signal transducers and secondary messengers such as adenylate cyclase and guanylate cyclase. These molecules stay inside cells and act as cofactors, important for signaling.
  5. Cofactors:
    Cofactors: Adenosine is present in all of the important ones. Adenosine does not participate in the chemical reaction. Removal of adenosine reduces cofactor function. The cofactors fit into a nucleotide-binding fold. May assist in substrate/active site induced fit.
  6. EXTRA ADDED: nucleotide-binding fold (rossman fold):
    Nucleotide-binding fold (the Rossman fold): it is a domain that is present in many enzymes and is specific for adenosine nucleotides over others. It is a binding motif or supersecondary structure. Area of a protein that binds nucleotides with specificity (as a motif, they are a pattern found in many proteins). It is composed of alternating beta strands (6) and alpha helices (4).