cooperative binding(Site not responding. Last check: 2007-10-13)
A model to explain the sigmoid shape of the curve is called the cooperativebinding model.
The term cooperativebinding derives from the property that the binding of one molecule of substrate makes it easier for the second molecule of substrate to bind.
An excellent example of cooperativebinding was discovered by Gehrhardt and Pardee in their study of the enzyme Aspartate transcarbamylase.
Protein Dimers and Cooperative Binding(Site not responding. Last check: 2007-10-13)
The active form of many enzymes, including the DNA binding proteins we propose using, is a bound combination of two copies of the protein.
A similar power law behavior is obtained in cooperativebinding of proteins to a substrate.
Cooperativebinding refers to mechanisms in which the first of several protein binding reactions occurs at a relatively low rate, while subsequent binding reactions occur more rapidly, because the presence of the already bound protein enhances the binding affinity.
binds to the R state at least 10,000-fold more tightly than to T. In this model, the dissociation constants of the two sites in the R state of the myristoylated protein are 0.11 and 6.9 µM, as in unmyristoylated recoverin.
Myristoylated recoverin cooperativelybinds two Ca with a Hill coefficient of 1.75 and an apparent dissociation constant of 17 µM. Unmyristoylated recoverin, by contrast, binds two Ca noncooperatively with markedly different affinities (0.11 and 6.9 µM).
The effect of the myristoyl group on the Ca bindingcooperativity is somewhat analogous to the effect of a target peptide on Ca binding to calmodulin.
A pair of sites for two different kinds of factors with cooperativebinding can be a simple module for signal integration, leading to the expression of the downstream gene only when both kinds of factors are present simultaneously [1].
The cooperativebinding of transcription factors involves protein-protein interactions which may be specific to the DNA substrate.
Despite this simplicity, the evolutionary dynamics of binding sites is far from trivial, since it is governed, in the generic case, by the interplay of three evolutionary forces: selection, mutation, and genetic drift.
Clark JH, Paszko Z, Peck EJ 1977 Nuclear binding and retention of the receptor estrogen complex: relation to the agonistic and antagonistic properties of estriol.
Estriol and estrone-induced inhibition of the cooperativebinding of [
Kumar V, Chambon P 1988 The oestrogen receptor binds tightly to its responsive element as a ligand-induced homodimer.
In vitro EXD/PBX serves as a Hoxb-1 cofactor in cooperativebinding and in Drosophila expression mediated by the r4 enhancer is dependent on both lab and exd.
Two regions that have been implicated in HOX/PBX cooperative interactions are the YPWM motif, found N-terminal to the HOX homeodomain, and the GKFQ domain (also known as the Hox cooperativity motif) immediately C-terminal to the PBX homeodomain.
Cooperativebinding to ATCAATCAA required the homeodomain-dependent DNA-binding activities of both Pbx1 and the Hox partner.
binding obtained in the absence and in the presence of TG was
binding was measured in the absence of ATP as described by Zhang et al.
Structural representation of the transmembrane helices involved in Ca binding, and its connection to the cytosolic phosphorylation domain, was obtained directly from the crystallographic structure of the SR ATPase with Ca bound (Toyoshima et al., 2000
to the iteron sequences in oriV (10, 26-28) and this binding
Linear template (2.5 ng) containing the wild-type oriV region was incubated with 31 ng of DnaA protein followed by DNase I treatment as described under "Experimental Procedures." Complexes I and II were separated by gel electrophoresis, isolated from the acrylamide gel, and analyzed on a 10% denaturing gel.
binding and it is this binding that is required for replication
Cooperativebinding of Sox10 to DNA: requirements and consequences -- Schlierf et al.
Oligonucleotides C/C' and C'mut [in which C is mutated so that cooperativebinding is lost, see Peirano and Wegner (12)] were used as probes as indicated below the lanes.
binding of a monomer to one half-site is not sufficient (12).
Cooperative DNA Binding and Sequence Discrimination by the Opaque2 bZIP Factor -- Yunes et al.
Cooperative DNA Binding and Sequence Discrimination by the Opaque2 bZIP Factor
Singh, K., Tokuhisa, J.G., Dennis, E.S., and Peacock, W.J. (1989) Saturation mutagenesis of the octopine synthase enhancer: Correlation of mutant phenotypes with binding of a nuclear protein factor.
Copper binding to the prion protein: Structural implications of four identical cooperative binding sites -- Viles et ...(Site not responding. Last check: 2007-10-13)
The binding of Cu(II), both to the octarepeat peptides and to the full length protein, is strongly pH-dependent.
The binding of imidazole groups and backbone amide nitrogens is common in other histidine-containing Cu(II) complexes.
It is unlikely that a single imidazole binds each copper ion because this would result in less stable complexes than are observed.
