The same kind of distribution was observed for the network that is formed by the non-DNA-binding dimerising interactions, where the hub was SHP [NR0B2] (see interactions_distribution worksheet in Additional file 1); the log-log plot linear regression R2 = 0.7427.
However, for metal binding or protein interactions where the activity does not need to be so exquisitely tailored to provide the precise stereochemistry of catalytic residues, most parts of the surface may be able to evolve the right characteristics for binding ligands/protein partners.
Consequently, they often mediate interactions where the biological requirements are such that a transient or dynamic binding event is preferable [ 10, 12].
Time resolved photoluminescence studies revealed the quenching involves a combined static and dynamic interaction where the binding constant and number of binding sites for NAD+ were 0.201 L mol−1 and 3.6, respectively.
However, in situations where binding interactions dominate during the recovery phase, general models have been reported that can yield informative kinetic parameters for protein binding to cellular structures (Bulinski et al., 2001; Sprague et al., 2004).
The regions of greatest non-complementarity between the enzyme and ligands are the portions of the ligand that make few polar contacts with the binding site, as well as the sites of chemical reaction, where overly strong electrostatic binding interactions with the substrate could hinder catalysis.
Renda, M. et al. Critical DNA binding interactions of the insulator protein CTCF: a small number of zinc fingers mediate strong binding, and a single finger-DNA interaction controls binding at imprinted loci.
For extension of applicability to more complex cases where cooperative binding interactions occur, (4) may be generalized to a form of the Hill equation [ 45, 46]: (5) f = 1 1 + (K D / [ Ab ] ) n, where n is an interaction coefficient whose value is a lower bound on the number of binding sites for antibody on the antigen.
Modulation of an interaction by modification of multiple residues even allows for rheostatic control of binding strength, where the affinity for an interaction partner is gradually altered by multiple modifications that additively enhance or diminish the interaction.
(D ) Illustration of Type I and Type II interactions, where pairs of condensin binding sites interact, or where one binding site interacts with up to two others, respectively.
