Kinesins were purified by adding the nonhydrolyzable analog AMP-PNP to cytoplasmic extracts containing microtubules, purifying the microtubules, and then releasing the kinesin proteins, which were still attached to the microtubules, by adding ATP
Would this trick have worked to purify myosin motors attached to actin filaments? Explain.
No, addition of a nonhydrolyzable form of ATP would not increase the affinity of myosin for actin. This is because when the myosin motor binds to ATP, the myosin head undergoes a conformational change that reduces its affinity for actin.
You might also like to view...
The site of DNA replication is localized to the ________ within the mitochondrion.
Fill in the blank(s) with the appropriate word(s).
A mutation in a ribosome binding site in the lac operon would likely result in
A) reduction in the amount of LacZ, LacY, or LacA protein. B) reduction in the amount of LacZ, LacY, and LacA proteins. C) complete loss of transcription of the lac operon. D) a lac mRNA that is shorter than wild-type.
Before a desired gene can be spliced into a bacterial plasmid cloning vector, the gene must first be from the original DNA.
A. precisely cut, with a restriction enzyme, B. glued, with ligase, C. injected into a bacterial cell or a virus, having different sequences D. injected into a stem cell, to determine any unwanted traits E. All of the answer choices are correct.
The respiratory quotient is calculated as the
A) sum of the volume of oxygen consumed and the volume of carbon dioxide produced. B) product of the volume of oxygen consumed and the volume of carbon dioxide produced. C) ratio of the volume of oxygen consumed per volume of carbon dioxide produced. D) product of the volume of carbon dioxide consumed and the volume of oxygen produced. E) ratio of the volume of carbon dioxide produced per volume of oxygen consumed.