  While many good textbooks are available on Protein Structure, Molecular
Simulations, Thermodynamics and Bioinformatics methods in general, there is no
good introductory level book for the field of Structural Bioinformatics. This
book aims to give an introduction into Structural Bioinformatics, which is
where the previous topics meet to explore three dimensional protein structures
through computational analysis. We provide an overview of existing
computational techniques, to validate, simulate, predict and analyse protein
structures. More importantly, it will aim to provide practical knowledge about
how and when to use such techniques. We will consider proteins from three major
vantage points: Protein structure quantification, Protein structure prediction,
and Protein simulation & dynamics.
  Within the living cell, protein molecules perform specific functions,
typically by interacting with other proteins, DNA, RNA or small molecules. They
take on a specific three dimensional structure, encoded by its amino acid
sequence, which allows them to function within the cell. Hence, the
understanding of a protein's function is tightly coupled to its sequence and
its three dimensional structure. Before going into protein structure analysis
and prediction, and protein folding and dynamics, here, we give a short and
concise introduction into the basics of protein structures.
