ISDA: 7PEO

ELECTRON MICROSCOPY

Sample

Structure of the Caulobacter crescentus S-layer protein RsaA N-terminal domain bound to LPS and soaked with Holmium

Specimen Preperation

Sample Aggregation State	PARTICLE
Vitrification Instrument	FEI VITROBOT MARK IV
Cryogen Name	ETHANE
Sample Vitrification Details	Vitrobot options: Blot time 4 seconds, Blot force -13,1, Wait time 10 seconds, Drain time 0.5 seconds,

3D Reconstruction

Reconstruction Method	SINGLE PARTICLE
Number of Particles	158430
Reported Resolution (Å)	4.37
Resolution Method	FSC 0.143 CUT-OFF
Other Details	The final map was obtained from 158,430 particles and post-processed using a soft mask focused on the inner fourteen subunits yielding a resolution of 4.37 A according to the gold standard Fourier shell correlation criterion of 0.143 (Scheres, 2012) with some anisotropy in Z as judged by directional FSCs (Tan et al., 2017)
Refinement Type
Symmetry Type	POINT

Map-Model Fitting and Refinement

ID	1
Refinement Space	REAL
Refinement Protocol	RIGID BODY FIT
Refinement Target	?
Overall B Value	?
Fitting Procedure	?
Details	The atomic coordinates (PDB ID 6T72) of our previous cryo-EM structure (von Kugelgen et al., 2020) of the RsaANTD oligomer bound to the O-antigen of lipopolysaccharide (LPS) were rigid body fitted into the final post-processed map from Relion 3.0 (Zivanov et al., 2018) using UCSF Chimera (Pettersen et al., 2004). The resulting fitted model was subjected to real-space refinement using Refmac5 (Murshudov et al., 2011) inside the CCP-EM suite (Burnely et al., 2017), as described previously (von Kugelgen et al., 2020), using reference restraints of the initial structure (PDB ID 6T72) generated with PROSMART (Nicholls et al. 2012).

Data Acquisition

Detector Type	GATAN K2 SUMMIT (4k x 4k)
Electron Dose (electrons/Å²)	44.8

Imaging Experiment

Date of Experiment	?
Temprature (Kelvin)
Microscope Model	FEI TITAN KRIOS
Minimum Defocus (nm)	-1000
Maximum Defocus (nm)	-4000
Minimum Tilt Angle (degrees)	?
Maximum Tilt Angle (degrees)	?
Nominal CS	2.7
Imaging Mode	BRIGHT FIELD
Specimen Holder Model	FEI TITAN KRIOS AUTOGRID HOLDER
Nominal Magnification	130000
Calibrated Magnification	130000
Source	FIELD EMISSION GUN
Acceleration Voltage (kV)	300
Imaging Details	EPU software

Imaging Experiment

Image Processing

CTF Correction Type	CTF Correction Details	Number of Particles Selected	Particle Selection Details
PHASE FLIPPING AND AMPLITUDE CORRECTION	RELION refinement with in-built CTF correction. The function is similar to a Wiener filter, so amplitude correction included.