Manual

The following sections briefly describe how to run SASRES from the command- line, the required input and the produced output file.

Introduction

SASRES is a tool for evaluating the quality and resolution of ab initio shape reconstructed using small-angle scattering (SAS) data. It employs a Fourier Shell Correlation (FSC) based approach to assess the resolution of a reconstruction using a pre-aligned ensemble of models. By leveraging the variability of multiple SAS models derived from a single dataset, it estimates the overall model resolution based on the fact that the average FSC function over an ensemble, which reflects model variability, correlates directly with the resolution of individual models.

Input models must be pre-aligned, either by DAMAVER or CIFSUP, or any other application capable of model superposition. The FSC is calculated pairwise between all input models, and the final FSC is the mean of these pairwise calculations, along with the standard error of the mean. The resolution threshold is set at FSC=0.5.

Running Sasres

Usage:

$ sasres [OPTIONS] <MODEL(S)>

SASRES accepts absolute as well as relative paths to the atomic coordinate MODEL in .pdb or .cif format.

The OPTIONS known by SASRES are described in the next section.

Command-Line Arguments and Options

SASRES requires the following command line arguments:

Argument Description
MODELS Three or more dummy atom models in .pdb or .cif format.

SASRES recognizes the following command-line options.

Short Option Long Option Description
  --model=<ID> Model ID in the coordinate file (default: all)
  --chain=<ID> Chain ID in the coordinate file (default: all)
-0 --output=<FILE> Output filename of the averaged FSC (default: stdout)
-v --version Print version information and exit.
-h --help Print a summary of arguments, options, and exit.

Runtime Output

There is no runtime output unless the FSC is written to stdout, as per default.

Sasres Input Files

SASRES requires at least an ensemble of three ab initio models in .pdb or .cif format as an input.

Sasres Output Files

SASRES computes the average FSC function and estimates the ensemble resolution. The results are written to stdout, or the file name specified with the output option.

Examples

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