PDBsum entry 1fqw

Signaling protein

PDB id: 1fqw

Contents

Protein chains

128 a.a. *

Ligands

BEF ×2

Metals

_MN ×2

Waters ×173

* Residue conservation analysis

PDB id:

1fqw

Name:

Signaling protein

Title:

Crystal structure of activated chey

Structure:

Chemotaxis chey protein. Chain: a, b. Engineered: yes

Source:

Escherichia coli. Organism_taxid: 562. Expressed in: escherichia coli. Expression_system_taxid: 562

Biol. unit:

Dimer (from PQS)

Resolution:

2.37Å R-factor: 0.210 R-free: 0.240

Authors:

S.Y.Lee,H.S.Cho,J.G.Pelton,D.Yan,E.A.Berry,D.E.Wemmer

Key ref:

S.Y.Lee et al. (2001). Crystal structure of activated CheY. Comparison with other activated receiver domains. J Biol Chem, 276, 16425-16431. PubMed id: 11279165 DOI: 10.1074/jbc.M101002200

Date:

07-Sep-00 Release date: 18-Jul-01

Protein chains

P0AE67  (CHEY_ECOLI) -  Chemotaxis protein CheY from Escherichia coli (strain K12)

Seq: 129 a.a.

Struc: 128 a.a.

Enzyme reactions

• Enzyme class: E.C.?

DOI no: 10.1074/jbc.M101002200

J Biol Chem 276:16425-16431 (2001)

PubMed id: 11279165

Crystal structure of activated CheY. Comparison with other activated receiver domains.

S.Y.Lee, H.S.Cho, J.G.Pelton, D.Yan, E.A.Berry, D.E.Wemmer.

ABSTRACT

The crystal structure of BeF(3)(-)-activated CheY, with manganese in the magnesium binding site, was determined at 2.4-A resolution. BeF(3)(-) bonds to Asp(57), the normal site of phosphorylation, forming a hydrogen bond and salt bridge with Thr(87) and Lys(109), respectively. The six coordination sites for manganese are satisfied by a fluorine of BeF(3)(-), the side chain oxygens of Asp(13) and Asp(57), the carbonyl oxygen of Asn(59), and two water molecules. All of the active site interactions seen for BeF(3)(-)-CheY are also observed in P-Spo0A(r). Thus, BeF(3)(-) activates CheY as well as other receiver domains by mimicking both the tetrahedral geometry and electrostatic potential of a phosphoryl group. The aromatic ring of Tyr(106) is found buried within a hydrophobic pocket formed by beta-strand beta4 and helix H4. The tyrosine side chain is stabilized in this conformation by a hydrogen bond between the hydroxyl group and the backbone carbonyl oxygen of Glu(89). This hydrogen bond appears to stabilize the active conformation of the beta4/H4 loop. Comparison of the backbone coordinates for the active and inactive states of CheY reveals that only modest changes occur upon activation, except in the loops, with the largest changes occurring in the beta4/H4 loop. This region is known to be conformationally flexible in inactive CheY and is part of the surface used by activated CheY for binding its target, FliM. The pattern of activation-induced backbone coordinate changes is similar to that seen in FixJ(r). A common feature in the active sites of BeF(3)(-)-CheY, P-Spo0A(r), P-FixJ(r), and phosphono-CheY is a salt bridge between Lys(109) Nzeta and the phosphate or its equivalent, beryllofluoride. This suggests that, in addition to the concerted movements of Thr(87) and Tyr(106) (Thr-Tyr coupling), formation of the Lys(109)-PO(3)(-) salt bridge is directly involved in the activation of receiver domains generally.

Selected figure(s)

Figure 1.
Fig. 1. Ribbon diagram of the two BeF[ - ]-activated CheY molecules in the asymmetric unit. The active sites are directed toward the reader. Side chains are shown for BeF[ - ]-Asp57, Thr87, and Tyr106.

Figure 3.
Fig. 3. Stereo view of the active site of BeF[ - ]-CheY. Carbon, nitrogen, oxygen beryllofluoride, and manganese atoms are colored gray, dark blue, red, yellow, and green, respectively. a, omit map contoured at 3.0 covering Asp12, Asp13, BeF[ - ]-Asp57, Thr87, Lys109, and two water molecules. This map was calculated with the occupancies for these residues set to zero. For clarity, the density for manganese is not shown. b, ball-and-stick diagram of the BeF[ - ]-activated CheY active site. Dashed lines and numbers denote active site interactions defined in Table II. c, stereo view of active site residues for BeF[ - ]-CheY(Mn2+) (blue), phosphorylated FixJr(no metal) (lime), and phosphorylated Spo0A^r(Ca^2+) (copper). Mn2+ and Ca^2+ are shown as red and green balls, respectively. Residue numbers are based on E. coli CheY. For clarity, phosphono-CheY was not included.

The above figures are reprinted by permission from the ASBMB: J Biol Chem (2001, 276, 16425-16431) copyright 2001.

Figures were selected by the author.