Get   for     ? 
 Site search     ? 
Catalytic Site Atlas Version 2.2.12
Find Annotated Site: PDB code:
Swiss-Prot code:
EC number:
Help
CSA entry for 1p5d
Original Entry
Title:
Isomerase
Compound:
Phosphomannomutase
Mutant:
No
UniProt/Swiss-Prot:
P26276-ALGC_PSEAE
EC Class:
5.4.2.8
Other CSA Entries:
Overview of all sites for 1p5d
Homologues of 1p5d
Entries for UniProt/Swiss-Prot: P26276
Entries for EC: 5.4.2.8
Other Databases:
PDB entry: 1p5d
PDBsum entry: 1p5d
UniProt/Swiss-Prot: P26276
IntEnz entry: 5.4.2.8
Literature Report:
Introduction:
Phosphomannomutase or phosphoglucomutase (PMM/PGM) from Pseudomonas aeruginosa can catalyse the same reaction in two different substrates. It catalyses the transfer of a phosphoryl group from the 6 position to the 1 position in either mannose 6-P or glucose 6-P. PMM/PGM activity is required for the biosynthesis of lipopolysaccharides in Pseudomonas aeruginosa.
Mechanism:
1. Residues Arg 20, His 109, Lys 118, Arg247 and His 329 along with cofactor Mg2+ form a positive electrostatic field. This decreases the pKa of the proton on the hydroxyl of C1 to such an extent as to cause spontaneous ionization.
2. The substrate O atom then nucleophilically attacks the phosphorus of Sep 108, which acts as an electrophile, and the Serine O-P bond is broken.
3. The above residues (and co-factor) then act to stabilise the Ser 108 alkoxide.
4. Rotation of the substrate occurs, arranging the C6 phospho group toward Ser 108.
5. Ser 108 then nucleophilically attacks the C6 phosphorus atom, breaking the P-O bond of the substrate.
6. The substrate is then re-protonated to form the 1-P product.
Sites:

Click to Display Catalytic Site (Get help with this section)
Found by:
Literature reference 

ResidueChainNumberUniProt numberFunctional part FunctionTargetDescription
500 0
ElectrostaticSubstrate
ElectrostaticResidue
Helps form a positive electrostatic field which decreases the pKa of the proton on the hydroxyl of C1 to such an extent as to cause spontaneous ionization. Also helps stabilise the Ser 108 alkoxide.
Evidence from paper Evidence concerns Evidence type
PubMed ID 14725765 Current protein Residue is positioned appropriately (ligand position known)

ResidueChainNumberUniProt numberFunctional part FunctionTargetDescription
ARGX 20 20Sidechain
ElectrostaticResidue
ElectrostaticSubstrate
Helps form a positive electrostatic field which decreases the pKa of the proton on the hydroxyl of C1 to such an extent as to cause spontaneous ionization. Also helps stabilise the Ser 108 alkoxide.
Evidence from paper Evidence concerns Evidence type
PubMed ID 12924943 Current protein Mutagenesis of residue
PubMed ID 12924943 Current protein Residue is positioned appropriately (ligand position known)

ResidueChainNumberUniProt numberFunctional part FunctionTargetDescription
SEPX 108 108Sidechain
NucleophileSubstrate
ElectrophileSubstrate
Sep 108 donates a phospho group to the C1 position, then removes a phospho group from the C6 position of the substrate.
Evidence from paper Evidence concerns Evidence type
PubMed ID 12924943 Current protein Mutagenesis of residue

ResidueChainNumberUniProt numberFunctional part FunctionTargetDescription
HISX 109 109Sidechain
ElectrostaticSubstrate
ElectrostaticResidue
Helps form a positive electrostatic field which decreases the pKa of the proton on the hydroxyl of C1 to such an extent as to cause spontaneous ionization. Also helps stabilise the Ser 108 alkoxide.
Evidence from paper Evidence concerns Evidence type
PubMed ID 12924943 Current protein Mutagenesis of residue
PubMed ID 12924943 Current protein Residue is positioned appropriately (ligand position known)

ResidueChainNumberUniProt numberFunctional part FunctionTargetDescription
LYSX 118 118Sidechain
ElectrostaticSubstrate
ElectrostaticResidue
Helps form a positive electrostatic field which decreases the pKa of the proton on the hydroxyl of C1 to such an extent as to cause spontaneous ionization. Also helps stabilise the Ser 108 alkoxide.
Evidence from paper Evidence concerns Evidence type
PubMed ID 12924943 Current protein Residue is positioned appropriately (ligand position known)
PubMed ID 12924943 Current protein Mutagenesis of residue

ResidueChainNumberUniProt numberFunctional part FunctionTargetDescription
ARGX 247 247Sidechain
ElectrostaticSubstrate
ElectrostaticResidue
Helps form a positive electrostatic field which decreases the pKa of the proton on the hydroxyl of C1 to such an extent as to cause spontaneous ionization. Also helps stabilise the Ser 108 alkoxide.
Evidence from paper Evidence concerns Evidence type
PubMed ID 12924943 Current protein Mutagenesis of residue
PubMed ID 12924943 Current protein Residue is positioned appropriately (ligand position known)

ResidueChainNumberUniProt numberFunctional part FunctionTargetDescription
HISX 329 329Sidechain
ElectrostaticSubstrate
ElectrostaticResidue
Helps form a positive electrostatic field which decreases the pKa of the proton on the hydroxyl of C1 to such an extent as to cause spontaneous ionization. Also helps stabilise the Ser 108 alkoxide.
Evidence from paper Evidence concerns Evidence type
PubMed ID 12924943 Current protein Mutagenesis of residue
PubMed ID 12924943 Current protein Residue is positioned appropriately (ligand position known)
Notes:

References:
1
Roles of active site residues in Pseudomonas aeruginosa phosphomannomutase/phosphoglucomutase.
L. E. Naught and C. Regni and L. J. Beamer and P. A. Tipton
Biochemistry 42, (33) 9946-51, (2003).
12924943
2
Structural basis of diverse substrate recognition by the enzyme PMM/PGM from P. aeruginosa.
C. Regni and L. Naught and P. A. Tipton and L. J. Beamer
Structure 12, (1) 55-63, (2004).
14725765
Which EBI biological databases are available and how do I access them? EBI Site Map