A proteolytic AAA+ machine poised to unfold protein substrates.

AAA+ proteolytic machines unfold proteins before degrading them. Here, we present cryoEM structures of ClpXP-substrate complexes that reveal a postulated but heretofore unseen intermediate in substrate unfolding/degradation. A ClpX hexamer draws natively folded substrates tightly against its axial channel via interactions with a fused C-terminal degron tail and ClpX-RKH loops that flexibly conform to the globular substrate.

Development and validation of a novel comorbidity score specific for prostate cancer patients treated with robotic platform and its implication on DaVinci single-port system.

To develop and validate a novel Comorbidity score for Robotic Surgery (CRS) in predicting severe complications after robot-assisted radical prostatectomy (RARP). Furthermore, we investigated the impact of the surgical platform (Multi-Port - MP vs Single-Port - SP) according to this score. We included 2085 ("development cohort") and 595 ("validation cohort") patients undergoing RARP at two tertiary referral centers between 2014 and March 2024 in a retrospective study.

How the double-ring ClpAP protease motor grips the substrate to unfold and degrade stable proteins.

Loops in the axial channels of ClpAP and other AAA+ proteases bind a short peptide degron connected by a linker to the N- or C-terminal residue of a native protein to initiate degradation. ATP hydrolysis then powers pore-loop movements that translocate these segments through the channel until a native domain is pulled against the narrow channel entrance, creating an unfolding force. Substrate unfolding is thought to depend on strong contacts between pore loops and a subset of amino acids in the unstructured sequence directly preceding the folded domain.