Figure 4

Models of HutD, HutC in different states and lipid embedded assembly. Ribbon representation of the models of (a) HutD dimer in the OF state, Nucleotide-binding domains (NBDs, dimer of HutD) are shown in brown and cyan, conserved Walker-A motif or P-Loop is shown in magenta of each NBD. Two ATP molecules are shown in stick; (b) HutD dimer in the IF state; (c) zoomed view of the docking of Mg²⁺-ATP in HutD OF dimer and related interactions; (d) Mg²⁺-ATP bound HutCD dimeric assembly in the OF state; zoomed view of different regions of HutCD are shown in (e–g). (e) Interactions between L-loop of HutC1 (salmon) with Q-loop of HutD1 (magenta); (f) disposition of binding motifs such as A-loop, Walker-A (green), Walker-B (maroon) around Mg²⁺-ATP. ABC signature motif is shown in cyan; (g) arrangements of transmembrane helices in HutCD-OF model is shown from the periplasmic side. TM5 helices of each TMD is shown in green, H5a in yellow; (h) Model of HutCD assembly in IF state. (i) Model of HutCD assembly embedded in solvated DMPC lipid bilayer.