Histidine Kinases in Signal Transduction

Preface

Contributors

1 Histidine Kinases: Introductory Remarks

Introduction

Basic Structure of Histidine Kinases (HKs)

Uniqueness of HKs

Difference between HKs and Ser/Thr/Tyr Kinases

Signal Transduction Mechanism

Regulation of Kinase and Phosphatase Activities: Switch Model and Rheostat Model

Concluding Remarks

References

2 The Histidine Kinase Family: Structures of Essential Building Blocks

Introduction

Kinase/Phosphatase Core Domain

Phosphotransfer Domain

Considerations on Domain Interactions

Concluding Remarks

References

3 Regulation of Porins in Escherichia coli by the Osmosensing Histidine Kinase~hosphatase EnvZ

Introduction

Domain A Is the Catalytic Domain

Domain B Is the Catalysis-Assisting and ATP-Binding Domain

Monomeric HistidineKinase: Topological Arrangement between Domain A and Domain B

Role of DNA in EnvZ Function

Stoichiometric Complex Formation between EnvZ and OmpR

Regulation of Kinase and Phosphatase Activities: Switch Model versus Rheostat Model

Mechanism of Osmoregulation

Concluding Remarks

References

4 Structure and Function of CheA, the Histidine Kinase Central to Bacterial Chemotaxis

Introduction

Modular Structure of CheA

A Superfamily of Histidine Kinases and ATPases

Nucleotide Binding by CheA P4 and the GHL ATPases

ATP Hydrolysis and Conformation of P4

HPt Domain P1 and Phosphoryl Transfer

P2 Domain and Response Regulator Coupling

A Separate Dimerization Domain

Receptor Coupling by the P5 Regulatory Domain

Is Flexibility between Domains Important for Signaling?

Controlling Protein-Protein Interactions with ATP

Prospects for the Design of Antibiotics Directed at CheA

What Is Next?

References

5 Transmembrane Signaling and the Regulation of Histidine Kinase Activity

Introduction

Membrane Receptor Kinases

Type I Histidine Kinase Receptors

Receptors with Several Membrane-Spanning