Phosphotransfer and CheY-Binding Domains of the Histidine Autokinase CheA Are Joined by a Flexible Linker

Hongjun Zhou; Megan M McEvoy; David F Lowry; Ronald V Swanson; Melvin I Simon; Frederick W Dahlquist

doi:10.1021/bi951960e

Back

Phosphotransfer and CheY-Binding Domains of the Histidine Autokinase CheA Are Joined by a Flexible Linker

Journal article

Open access

Peer reviewed

Phosphotransfer and CheY-Binding Domains of the Histidine Autokinase CheA Are Joined by a Flexible Linker

Hongjun Zhou, Megan M McEvoy, David F Lowry, Ronald V Swanson, Melvin I Simon and Frederick W Dahlquist

Biochemistry (Easton), Vol.35(2), pp.433-443

01/16/1996

DOI: https://doi.org/10.1021/bi951960e

Handle:

https://hdl.handle.net/2376/115060

PMID: 8555213

Files and links (1)

url

https://doi.org/10.1021/bi951960eView

Published (Version of record) Open

Abstract

Multidimensional heteronuclear NMR techniques were applied to study a protein fragment of the histidine autokinase CheA from Escherichia coli. This fragment (CheA1-233) contains the phosphotransfer domain and the CheY-binding domain joined by a linker region. Comparison of chemical shift and NOE cross-peak patterns indicates that the structures of the two domains in CheA1-233 remain nearly the same as in the two individual domain fragments, CheA1-134 and CheA124-257. Relaxation properties of the backbone 15N nuclei were measured to study the rotational correlations of the two domains and properties of the linker region. Dynamics data were analyzed both by an isotropic motional model and an anisotropic motional model. The experimental T 1 and T 2 values, the derived rotational correlation times, and motional anisotropy are significantly different for the two domains, indicating the two domains reorient independently and the linker region is highly flexible. Dynamics data of CheA1-233 were also compared with those of CheA1-134. Our studies show that flexible domain linkers and extended and flexible terminal polypeptide chains can have significant effects on the motional properties of the adjacent structured regions. These observations suggest a model for the graded regulation of CheA autophosphorylation activity. In this model, the various activity states of the receptor are generated by controlling the access of the mean position of the kinase domain to the phosphotransfer domain. This would then modulate the diffusional encounter rate of the domains and hence activity over a wide and graded range of values.

Metrics

5 Record Views

Details

Title: Phosphotransfer and CheY-Binding Domains of the Histidine Autokinase CheA Are Joined by a Flexible Linker
Creators: Hongjun Zhou
Megan M McEvoy
David F Lowry
Ronald V Swanson
Melvin I Simon
Frederick W Dahlquist
Publication Details: Biochemistry (Easton), Vol.35(2), pp.433-443
Academic Unit: Engineering and Applied Sciences (TRIC), School of
Publisher: American Chemical Society
Identifiers: 99900547679701842
Language: English
Resource Type: Journal article