ATP synthase catalyzes synthesis of ATP through a mechanism in which part of the enzyme (the rotor, which includes the γ subunit) rotates relative to another part (the stator, which includes the β subunit). The following paper describes experiments that provide evidence for this rotary mechanism:
Y Zhou, TM Duncan, and RL Cross (1997) âSubunit rotation in Escherichia coli FoF1- ATP synthase during oxidative phosphorylation.â Proceedings of the National Academy of Sciences of the USA 94:10583-10587.
The experimental work involved generating an artificial (that is, not present in the wild type enzyme) disulfide bond between γ and one of the three β subunits, while the other two copies of β were modified with a âFLAGâ epitope tag. The researchers reduced the disulfide bond, allowed the enzyme to make ATP, re-formed the disulfide, and used antibodies recognizing the FLAG epitope to see whether γ was cross-linked to any of the FLAG-tagged β.
Using your knowledge of ATP synthase from this course and the information given above and in the cited paper, write a brief explanation of the rotary mechanism of ATP synthase, and how this experiment provides evidence for it, in terms that an average member of the public would understand. You might imagine trying to explain the basic mechanism of ATP synthase to a (non-scientist) member of your family, and using the experiment described in the paper to answer the natural follow-up question, âHow do they know that part of the thing rotates like that?â
ATP synthase catalyzes synthesis of ATP through a mechanism in which part of the enzyme (the rotor, which includes the γ subunit) rotates relative to another part (the stator, which includes the β subunit). The following paper describes experiments that provide evidence for this rotary mechanism:
Y Zhou, TM Duncan, and RL Cross (1997) âSubunit rotation in Escherichia coli FoF1- ATP synthase during oxidative phosphorylation.â Proceedings of the National Academy of Sciences of the USA 94:10583-10587.
The experimental work involved generating an artificial (that is, not present in the wild type enzyme) disulfide bond between γ and one of the three β subunits, while the other two copies of β were modified with a âFLAGâ epitope tag. The researchers reduced the disulfide bond, allowed the enzyme to make ATP, re-formed the disulfide, and used antibodies recognizing the FLAG epitope to see whether γ was cross-linked to any of the FLAG-tagged β.
Using your knowledge of ATP synthase from this course and the information given above and in the cited paper, write a brief explanation of the rotary mechanism of ATP synthase, and how this experiment provides evidence for it, in terms that an average member of the public would understand. You might imagine trying to explain the basic mechanism of ATP synthase to a (non-scientist) member of your family, and using the experiment described in the paper to answer the natural follow-up question, âHow do they know that part of the thing rotates like that?â
