PDBsum entry 1vkr

Transferase

PDB id: 1vkr

Contents

Protein chain

97 a.a. *

* Residue conservation analysis

PDB id:

1vkr

Name:

Transferase

Title:

Structure of iib domain of the mannitol-specific permease enzyme ii

Structure:

Mannitol-specific pts system enzyme iiabc components. Chain: a. Fragment: iib domain. Synonym: iibmtl phosphotransferase enzyme ii, b component, eiib-mtl. Engineered: yes

Source:

Escherichia coli. Organism_taxid: 83334. Strain: o157:h7. Expressed in: escherichia coli. Expression_system_taxid: 562

NMR struc:

1 models

Authors:

G.M.Clore,P.M.Legler,M.Cai

Key ref:

P.M.Legler et al. (2004). Three-dimensional solution structure of the cytoplasmic B domain of the mannitol transporter IImannitol of the Escherichia coli phosphotransferase system. J Biol Chem, 279, 39115-39121. PubMed id: 15258141 DOI: 10.1074/jbc.M406764200

Date:

14-Jun-04 Release date: 21-Sep-04

Protein chain

P00550  (PTM3C_ECOLI) -  PTS system mannitol-specific EIICBA component from Escherichia coli (strain K12)

Seq: 637 a.a.

Struc: 97 a.a.

Enzyme reactions

• Enzyme class: E.C.2.7.1.197 - protein-N(pi)-phosphohistidine--D-mannitol phosphotransferase.
• Reaction: D-mannitol(out) + N(pros)-phospho-L-histidyl-[protein] = D-mannitol 1-phosphate(in) + L-histidyl-[protein]

Molecule diagrams generated from .mol files obtained from the KEGG ftp site

Key reference

DOI no: 10.1074/jbc.M406764200

J Biol Chem 279:39115-39121 (2004)

PubMed id: 15258141

Three-dimensional solution structure of the cytoplasmic B domain of the mannitol transporter IImannitol of the Escherichia coli phosphotransferase system.

P.M.Legler, M.Cai, A.Peterkofsky, G.M.Clore.

ABSTRACT

The solution structure of the cytoplasmic B domain of the mannitol (Mtl) transporter (II(Mtl)) from the mannitol branch of the Escherichia coli phosphotransferase system has been solved by multidimensional NMR spectroscopy with extensive use of residual dipolar couplings. The ordered IIB(Mtl) domain (residues 375-471 of II(Mtl)) consists of a four-stranded parallel beta-sheet flanked by two helices (alpha(1) and alpha(3)) on one face and helix alpha(2) on the opposite face with a characteristic Rossmann fold comprising two right-handed beta(1)alpha(1)beta(2) and beta(3)alpha(2)beta(4) motifs. The active site loop is structurally very similar to that of the eukaryotic protein tyrosine phosphatases, with the active site cysteine (Cys-384) primed in the thiolate state (pK(a) < 5.6) for nucleophilic attack at the phosphorylated histidine (His-554) of the IIA(Mtl) domain through stabilization by hydrogen bonding interactions with neighboring backbone amide groups at positions i + 2/3/4 from Cys-384 and with the hydroxyl group of Ser-391 at position i + 7. Modeling of the phosphorylated state of IIB(Mtl) suggests that the phosphoryl group can be readily stabilized by hydrogen bonding interactions with backbone amides in the i + 2/4/5/6/7 positions as well as with the hydroxyl group of Ser390 at position i + 6. Despite the absence of any significant sequence identity, the structure of IIB(Mtl) is remarkably similar to the structures of bovine protein tyrosine phosphatase (which contains two long insertions relative to IIB(Mtl)) and the cytoplasmic B component of enzyme II(Chb), which fulfills an analogous role to IIB(Mtl) in the N,N'-diacetylchitobiose branch of the phosphotransferase system. All three proteins utilize a cysteine residue in the nucleophilic attack of a phosphoryl group covalently bound to another protein.

Selected figure(s)

Figure 2.
FIG. 2. Comparison of the polypeptide folds of IIB^Mtl, BPTP, and IIB^Chb. Ribbon diagrams showing two approximately orthogonal views of IIB^Mtl (red)(A), BPTP (B), and IIB^Chb (C). In panels B and C the regions of the polypeptide of BPTP and IIB^Chb, respectively, that superimpose on IIB^Mtl are shown in blue with the remainder in gray. Also shown in each case is the location of the active site cysteine. Single-letter amino acid abbreviations are used. For IIB^Mtl and BPTP (PDB accession code 1DG9 [PDB] ) (64), the C[ ]atoms of 81 residues (sequence identity 12.3%) superimpose with an r.m.s. difference of 1.9 Å; for IIB^Mtl and IIB^Chb (PDB accession code 1H9C [PDB] ) (19), the C[ ]atoms of 74 residues (sequence identity 8.1%) superimpose with an r.m.s. difference of 2.0 Å. (The structural alignments are as follows: residues 378-411, 411-417, 422-429, 429-444, 444-450, and 455-466 of IIB^Mtl superimpose on residues 6-39, 40-46, 83-90, 91-103, 111-117, and 146-157, respectively of BPTP; residues 378-385, 386-408, 409-420, 421-430, and 431-451 of IIB^Mtl superimpose on residues 4-11, 11-33, 33-44, 48-57, and 61-81, respectively of IIB^Chb).

Figure 3.
FIG. 3. The active site of IIB^Mtl. A, stereo view of the active site with the backbone in light blue, side chains in red, Cys-384 in orange, and the backbone NH bonds in dark blue with the H[N] protons represented by small spheres. B, possible mechanism of phosphoryl transfer from IIA^Mtl to IIB^Mtl. Single-letter amino acid abbreviations are used with position numbers.

The above figures are reprinted by permission from the ASBMB: J Biol Chem (2004, 279, 39115-39121) copyright 2004.

Figures were selected by an automated process.