Each heavy chain of this heterotetrameric protein consists of a head connected by a “neck linker” to a stalk ending in a C-terminal tail. For 10 points each:
[10m] Name this protein family whose “walking” motion has been proposed to proceed via either a “hand-over-hand” or “inchworm” mechanism.
ANSWER: kinesins [prompt on motor proteins; accept kinesin motor domain superfamily]
[10e] Experiments to determine the true mechanism of “walking” kinesin used constructs with solvent-exposed residues mutated to this amino acid, whose sulfhydryl group can be conjugated to Cy3 (“sigh three”) or Cy5 (“sigh five”).
ANSWER: cysteine [or Cys; or C]
[10h] Cy3 and Cy5 are a popular pair of dyes for this nanometer-scale technique. Rice et al.’s paper suggesting hand-over-hand motion used this technique to demonstrate the kinesin neck linker’s motion when kinesin binds ATP.
ANSWER: smFRET [or single-molecule fluorescence resonance energy transfer; or single-molecule Förster resonance energy transfer; prompt on FRET or fluorescence resonance energy transfer or Förster resonance energy transfer
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