1E6L

Two-component signal transduction system D13A mutant of CheY

Summary for 1E6L

• Entry DOI: 10.2210/pdb1e6l/pdb
• Related: 1A0O 1AB5 1AB6 1BDJ 1C4W 1CEY 1CHN 1CYE 1D4Z 1DJM 1E6K 1E6M 1EAY 1EHC 1HEY 1UDR 1VLZ 1YMU 1YMV 3CHY 5CHY 6CHY
• Descriptor: Chemotaxis protein CheY (2 entities in total)
• Functional Keywords: signaling protein, two-component signal transduction system, chemotaxis, active site mutant
• Biological source: Escherichia coli
• Total number of polymer chains: 1
• Total formula weight: 13866.05

Authors

Sola, M.,Lopez-Hernandez, E.,Cronet, P.,Lacroix, E.,Serrano, L.,Coll, M.,Parraga, A. (deposition date: 2000-08-18, release date: 2001-03-05, Last modification date: 2024-05-08)

Primary citation

Sola, M.,Lopez-Hernandez, E.,Cronet, P.,Lacroix, E.,Serrano, L.,Coll, M.,Parraga, A.
Towards understanding a molecular switch mechanism: thermodynamic and crystallographic studies of the signal transduction protein CheY.
J.Mol.Biol., 303:213-225, 2000

PubMed Abstract: The signal transduction protein CheY displays an alpha/beta-parallel polypeptide folding, including a highly unstable helix alpha4 and a strongly charged active site. Helix alpha4 has been shown to adopt various positions and conformations in different crystal structures, suggesting that it is a mobile segment. Furthermore, the instability of this helix is believed to have functional significance because it is involved in protein-protein contacts with the transmitter protein kinase CheA, the target protein FliM and the phosphatase CheZ. The active site of CheY comprises a cluster of three aspartic acid residues and a lysine residue, all of which participate in the binding of the Mg(2+) needed for the protein activation. Two steps were followed to study the activation mechanism of CheY upon phosphorylation: first, we independently substituted the three aspartic acid residues in the active site with alanine; second, several mutations were designed in helix alpha 4, both to increase its level of stability and to improve its packing against the protein core. The structural and thermodynamic analysis of these mutant proteins provides further evidence of the connection between the active-site area and helix alpha 4, and helps to understand how small movements at the active site are transmitted and amplified to the protein surface.

PubMed: 11023787
DOI: 10.1006/jmbi.2000.4507

Experimental method

X-RAY DIFFRACTION (1.9 Å)