text: user12686: 
  High–quality protein backbone reconstruction from alpha carbons using Gaussian mixture models
  
  The above research paper is about a software tool for reconstructing a protein's main chain model only from its alpha-carbon backbone (aka, C-alpha trace).
  This tool provides two options: conversion (1) with energy minimization, and (2) without energy minimization.
  
  Energy Minimization
  
  The above paper says that:
  
  ...
  The goal of energy Minimization is to find a set of coordinates representing the minimum energy conformation for the given structure.
  ...
  In molecular modeling we tend to are particularly curious about minimum points on the energy surface. Minimum energy arrangements of the atoms correspond to stable states of the system; any movement off from a minimum provides a configuration with a better energy.
  ...
  
  I haven't understood the quote from the second paper.
  Why do we need to know the minimum energy conformation of a protein chain? I.e., why do we want to do energy minimization?
  
  user14627: After translation, proteins fold to achieve a specific 3D structure which allows them to perform their specific functions. The structure of a protein computationally inferred through energy minimization often corresponds quite well to that specific, real-life folded 3D structure.
  If you are interested in the exact reason why proteins tend to fold to a conformation of minimal energy (even though this is an oversimplification of what's really happening) you would have to dive a bit deeper into the thermodynamics of proteins: https://en.wikipedia.org/wiki/Protein_dynamics
  TL;DR: Energy minimization is often used to get an idea of the protein's real-life conformation (i.e. structure) through computational means.
  
original_text: 12686: <ul>
  <li><a href="https://onlinelibrary.wiley.com/doi/10.1002/jcc.23330" rel="nofollow noreferrer">High–quality protein backbone reconstruction from alpha carbons using Gaussian mixture models</a></li>
  </ul>
  <p>The above research paper is about a software tool for reconstructing a protein's main chain model only from its alpha-carbon backbone (aka, C-alpha trace).</p>
  <p>This tool provides two options: conversion (1) with energy minimization, and (2) without energy minimization.</p>
  <ul>
  <li><a href="https://www.intechopen.com/chapters/74105" rel="nofollow noreferrer">Energy Minimization</a></li>
  </ul>
  <p>The above paper says that:</p>
  <blockquote>
  <p>...<br />
  The goal of energy Minimization is to find a set of coordinates representing the minimum energy conformation for the given structure.<br />
  ...<br />
  In molecular modeling we tend to are particularly curious about minimum points on the energy surface. Minimum energy arrangements of the atoms correspond to stable states of the system; any movement off from a minimum provides a configuration with a better energy.<br />
  ...</p>
  </blockquote>
  <p>I haven't understood the quote from the second paper.</p>
  <p>Why do we need to know the minimum energy conformation of a protein chain? I.e., why do we want to do <em>energy minimization</em>?</p>
   14627: <p>After translation, proteins fold to achieve a specific 3D structure which allows them to perform their specific functions. The structure of a protein computationally inferred through energy minimization often corresponds quite well to that specific, real-life folded 3D structure.</p>
  <p>If you are interested in the exact reason why proteins tend to fold to a conformation of minimal energy (even though this is an oversimplification of what's really happening) you would have to dive a bit deeper into the thermodynamics of proteins: <a href="https://en.wikipedia.org/wiki/Protein_dynamics" rel="noreferrer">https://en.wikipedia.org/wiki/Protein_dynamics</a></p>
  <p><strong>TL;DR: Energy minimization is often used to get an idea of the protein's real-life conformation (i.e. structure) through computational means.</strong></p>
  