  Considering all the PDB annotated allosteric proteins (from ASD - AlloSteric
Database) belonging to four different classes (kinases, nuclear receptors,
peptidases and transcription factors), this work has attempted to decipher
certain consistent patterns present in the residues constituting the allosteric
communication sub-system (ACSS). The thermal fluctuations of hydrophobic
residues in ACSSs were found to be significantly higher than those present in
the non-ACSS part of the same proteins, while polar residues showed the
opposite trend.
  The basic residues and hydroxyl residues were found to be slightly more
predominant than the acidic residues and amide residues in ACSSs, hydrophobic
residues were found extremely frequently in kinase ACSSs. Despite having
different sequences and different lengths of ACSS, they were found to be
structurally quite similar to each other - suggesting a preferred structural
template for communication. ACSS structures recorded low RMSD and high Akaike
Information Criterion(AIC) scores among themselves. While the ACSS networks for
all the groups of allosteric proteins showed low degree centrality and
closeness centrality, the betweenness centrality magnitudes revealed nonuniform
behavior. Though cliques and communities could be identified within the ACSS,
maximal-common-subgraph considering all the ACSS could not be generated,
primarily due to the diversity in the dataset. Barring one particular case, the
entire ACSS for any class of allosteric proteins did not demonstrate "small
world" behavior, though the sub-graphs of the ACSSs, in certain cases, were
found to form small-world networks.
