PDBsum entry 1eay

Signal transduction complex

PDB id: 1eay

Contents

Protein chains

128 a.a. *

67 a.a. *

Waters ×124

* Residue conservation analysis

References listed in PDB file

Key reference

Title

Two binding modes reveal flexibility in kinase/response regulator interactions in the bacterial chemotaxis pathway.

Authors

M.M.Mcevoy, A.C.Hausrath, G.B.Randolph, S.J.Remington, F.W.Dahlquist.

Ref.

Proc Natl Acad Sci U S A, 1998, 95, 7333-7338. [DOI no: 10.1073/pnas.95.13.7333]

PubMed id

9636149

Abstract

The crystal structure at 2.0-A resolution of the complex of the Escherichia coli chemotaxis response regulator CheY and the phosphoacceptor-binding domain (P2) of the kinase CheA is presented. The binding interface involves the fourth and fifth helices and fifth beta-strand of CheY and both helices of P2. Surprisingly, the two heterodimers in the asymmetric unit have two different binding modes involving the same interface, suggesting some flexibility in the binding regions. Significant conformational changes have occurred in CheY compared with previously determined unbound structures. The active site of CheY is exposed by the binding of the kinase domain, possibly to enhance phosphotransfer from CheA to CheY. The conformational changes upon complex formation as well as the observation that there are two different binding modes suggest that the plasticity of CheY is an essential feature of response regulator function.

Figure 3.
Fig. 3. Active site region of CheY. The overlay of CheY free (dark) and P2-bound (light) was based on a superposition of the entire -carbon backbone.

Figure 4.
Fig. 4. Sequence alignment of CheY and the response regulator domain of CheB. The interface forming residues in CheY of either heterodimer have a bar over the residue. Those residues that form side-chain hydrogen bonds in either heterodimer are indicated by above the residue.