Fig. 2: Structural organization of the Wza-Wzc complex.
From: Molecular insights into the capsular polysaccharide transporter Wza-Wzc complex
a Cryo-EM density map of Wza-WzcK540M complex. Bound ADP-Mg2+ is labeled. EM density of DDM micelles is shown in transparent blue. Wza EM density map is shown in tomato red; Wzc EM density map is shown in green. b Cross-section of the cryo-EM density map of the Wza-WzcK540M complex. c Atomic model of Wza-WzcK540M complex with individual subdomains labeled. TM - transmembrane domain; D1, D2, D3 - domains 1, 2, 3; Y-kinase - Tyrosine auto-kinase domain. d Loop-mediated interactions at the Wza and WzcK540M (AC interface). Key residues of the AC interface are indicated with sticks and labeled. e Charged residues located at the oligomerization surface interface and at the narrowest region of the periplasmic channel. Key structural elements of Wzc targeted for site-directed mutagenesis are colored in green. f Mutational analysis of essential structural elements in Wzc. ΔJR indicates deletion of the JR domain (residues 112–204), replaced with a GGGGS linker; AC refers to the AC interface mutant (WzcK332E,Y334A,T335A,H338E). CPS (colanic acid) production levels are presented as filled black circles, representing the mean ± s.d. from three independent biological replicates. Each circle denotes the average of three technical replicates. Statistical analysis was performed on biological replicate means using one-way ANOVA by the nonparametric Dunnett test in GraphPad Prism. Statistical differences were defined as * P ≤ 0.05, ** P ≤ 0.01, *** P ≤ 0.001, and ns (not significant) P > 0.05.
