ClpXP is an ATP-dependent protease in which the ClpX AAA+ motor binds, unfolds, and translocates specific protein substrates into the degradation chamber of ClpP. We present cryo-EM studies of the E. coli enzyme that show how asymmetric hexameric rings of ClpX bind symmetric heptameric rings of ClpP and interact with protein substrates. Subunits in the ClpX hexamer assume a spiral conformation and interact with two-residue segments of substrate in the axial channel, as observed for other AAA+ proteases and protein-remodeling machines.Strictly sequential models of ATP hydrolysis and a power stroke that moves two residues of the substrate per translocation step have been inferred from these structural features for other AAA+ unfoldases, but biochemical and single-molecule biophysical studies indicate that ClpXP operates by a probabilistic mechanism in which five to eight residues are translocated for each ATP hydrolyzed. We propose structure-based models that could account for the functional results.

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Purpose Supply chain flexibility is crucial for firms to respond to uncertain circumstances caused by environmental factors, such as the diversity of customer demands, problems of product safety, and adjustments of industrial policies. To investigate the approach to enhance supply chain flexibility, the purpose of this paper is to propose that both internal and external information integration contribute to reactive and proactive supply chain flexibilities, which elicit high operational performance. Design/methodology/approach Using a sample of 84 food companies that have been listed three years in China and content analysis based on their annual reports, evidence was collected to test the hypotheses through hierarchical regressions. Findings The results reveal that external information integration results in both reactive and proactive flexibilities, which further improve operational performance. Internal information integration positively affects both reactive and proactive flexibilities, but its mediating role was not determined in the study. Originality/value The research provides insights into how supply chain flexibility mediates the effect of supply chain information integration on operational performance in the context of the Chinese food industry.

Infants with cleft lip and palate, left cleft lip and alveolus, combined bilateral cleft lip and palate, micrognathia, and age <6 months were the important risk factors for difficult laryngoscopy. Difficult intubation occurred mainly in infants with laryngoscopic views of grade III and IV.