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Our molecular motions database serves a wide variety of purposes, helping investigators
understand the motion characteristics of individual proteins, as well as statistical
properties of large groups of motions. It is the ideal platform for the current study, since
it contains over 19000 morphs. A morph is a set of atomic coordinates for two
homologous protein structures (usually obtained experimentally), plus several structures
which our morph server generates as interpolations between the two. Our server displays
these structures in succession as a “movie” which suggests a possible trajectory of motion
between the two conformations. In this study we compiled two representative sets of
morphs with hinge annotation: a computer annotated set and a manually annotated set,
the Hinge Atlas, as will be explained. Using mostly the latter, we addressed the following
questions:
Are certain residue types differentially represented in hinges?
Do certain pairs of amino acids coincide with hinges?
Can sequence be used to predict hinges?
Do hinges coincide with active sites?
Do hinges prefer certain secondary structural elements?
Do hinge residues share physicochemical or steric properties?
Are hinge residues conserved in evolution?
As our first task, we computed the rate of occurrence of each residue type in the Hinge
Atlas. Certain amino acids were found to be differentially represented in hinges in a
statistically significant fashion. We also investigated whether certain consecutive pairs of
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