Which of the following describes the steps required prior to ATP-dependent degradation of proteins?
(I)Ubiquitin is transferred to cysteine on a ubiquitin-conjugating enzyme.
(II)The protein is linked to at least four tandemly linked ubiquitin units.
(III)Activated ubiquitin is transferred to a lysine of the previously bound protein.
(IV)Ubiquitin is attached via a thioester to a unbiquitin-activiating enzyme.

Question

Quizplus · Accepted Answer

The correct sequence for the ubiquitin-proteasome pathway involves first activating ubiquitin and attaching it to a ubiquitin-activating enzyme (E1), then transferring it to a ubiquitin-conjugating enzyme (E2), and finally, it is linked to the target protein often through the action of a ubiquitin ligase (E3), which typically involves the attachment of a chain of ubiquitin molecules to a lysine residue on the target protein. This process is necessary for the protein to be recognized and degraded by the proteasome.

Which of the Following Describes the Steps Required Prior to ATP-Dependent