EM structures and schematic of the catalytic core sub-complex containing Snf2, Arp7/9 and Rtt102 that are fitted by the crystal structure of Snf2 HSA-Arp7-Arp9 and Rtt102 (PDB ID: 4I6M) (Schubert et al., 2013) and Snf2 post-HSA-ATPase-SnAc domains (PDBID: 5HZR) (Xia et al., 2016) highlighting the substantial mobility of the ATPase domain (bottom panel).
The central cavity is closed at the external face, a finding that was also observed in the EM structures and from cross-linking data for cysteine containing mutants of P-gp.
It was not clear whether this funnel is seen in the putative outward facing conformation derived from the 3D EM structure, and the authors do not discuss the significance of its dimensions.
The coiled-coil, OB, ATPase domains and the HbYX motif are well defined in crystal and cryo-EM structures, and their primary sequences are highly conserved through evolution (Djuranovic et al., 2009; Chen et al., 2016; Huang et al., 2016; Schweitzer et al., 2016).
In contrast, Δ rimM predominantly contains Group III intermediates in which the head domain is anchored and only partially formed, consistent with head-formation defects observed in cryo-EM structures and by in vivo 16S hydroxyl radical footprinting (Clatterbuck Soper et al., 2013; Guo et al., 2013; Leong et al., 2013).
Armache, J.P. et al. Cryo-EM structure and rRNA model of a translating eukaryotic 80S ribosome at 5.5-Å resolution.
Indeed, we also provided evidences that the herein newly obtained model is comparable to the recently published human ABCG2 cryo-EM structure and that it performed better than a previously published one42, when evaluated using available structure assessment and validation computational tools.
While these studies establish the importance of the PTC-proximal and the mid-tunnel regions of the nascent MifM in the elongation arrest, the more N-terminal MifM residues were not visible in the cryo-EM structure and their roles remain to be investigated.
Are there any differences in the rotamer conformations between your cryo-EM structure and the 1.9 Å X-ray structure?
A recent cryo-EM structure and model of the yeast PIC appears consistent with such accommodation (Murakami et al. 2013).
In this study, we have determined six 3D EM structures of dynein and dynein Lis1 in different nucleotide states.
