6KGD image
Entry Detail
PDB ID:
6KGD
Keywords:
Title:
Crystal structure of CaDoc0917(R49D)-CaCohA2 complex at pH 8.0
Biological Source:
PDB Version:
Deposition Date:
2019-07-11
Release Date:
2020-07-08
Method Details:
Experimental Method:
Resolution:
1.65 Å
R-Value Free:
0.18
R-Value Work:
0.15
R-Value Observed:
0.15
Space Group:
P 21 21 21
Macromolecular Entities
Polymer Type:polypeptide(L)
Description:Probably cellulosomal scaffolding protein, secreted cellulose-binding and cohesin domain
Chain IDs:A
Chain Length:150
Number of Molecules:1
Biological Source:Clostridium acetobutylicum ATCC 824
Polymer Type:polypeptide(L)
Description:And cellulose-binding endoglucanase family 9 CelL ortholog dockerin domain
Mutations:R49D
Chain IDs:B
Chain Length:62
Number of Molecules:1
Biological Source:Clostridium acetobutylicum ATCC 824
Ligand Molecules
Primary Citation
Discovery and mechanism of a pH-dependent dual-binding-site switch in the interaction of a pair of protein modules.
Sci Adv 6 ? ? (2020)
PMID: 33097546 DOI: 10.1126/sciadv.abd7182

Abstact

Many important proteins undergo pH-dependent conformational changes resulting in "on-off" switches for protein function, which are essential for regulation of life processes and have wide application potential. Here, we report a pair of cellulosomal assembly modules, comprising a cohesin and a dockerin from Clostridium acetobutylicum, which interact together following a unique pH-dependent switch between two functional sites rather than on-off states. The two cohesin-binding sites on the dockerin are switched from one to the other at pH 4.8 and 7.5 with a 180° rotation of the bound dockerin. Combined analysis by nuclear magnetic resonance spectroscopy, crystal structure determination, mutagenesis, and isothermal titration calorimetry elucidates the chemical and structural mechanism of the pH-dependent switching of the binding sites. The pH-dependent dual-binding-site switch not only represents an elegant example of biological regulation but also provides a new approach for developing pH-dependent protein devices and biomaterials beyond an on-off switch for biotechnological applications.

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Primary Citation of related structures