Crystallization (Comment) | Organism |
---|---|
purified enzyme in complex with by-product UDP-xylo-sugar from 10 mM Tris-HCl. pH 9.0, 30 mM NaCl, and 1 mM DTT, suitable crystals are soaked in mother liquor supplemented with 25% v/v glycerol and 0.5 mlM UDP-D-GlcNAc, X-ray diffraction structure determination and analysis at 1.88 A resolution. The structure of CapE is virtually identical to that of apo-CapE in complex with a substrate analogue | Staphylococcus aureus |
Protein Variants | Comment | Organism |
---|---|---|
F78W | site-directed mutagenesis of a cofactor binding residue, the mutant shows similar activity compared to the wild-type enzyme | Staphylococcus aureus |
L122F | site-directed mutagenesis of a cofactor binding residue, the mutant shows reduced activity compared to the wild-type enzyme | Staphylococcus aureus |
Y164A | site-directed mutagenesis of a cofactor binding residue, the mutant shows highly reduced activity compared to the wild-type enzyme | Staphylococcus aureus |
Y164F | site-directed mutagenesis of a cofactor binding residue, the mutant shows markedly reduced activity compared to the wild-type enzyme | Staphylococcus aureus |
Natural Substrates | Organism | Comment (Nat. Sub.) | Natural Products | Comment (Nat. Pro.) | Rev. | Reac. |
---|---|---|---|---|---|---|
UDP-N-acetyl-alpha-D-glucosamine | Staphylococcus aureus | - |
UDP-2-acetamido-2,6-dideoxy-beta-L-arabino-hex-4-ulose + H2O | - |
? |
Organism | UniProt | Comment | Textmining |
---|---|---|---|
Staphylococcus aureus | A0A0H3JPH0 | - |
- |
Reaction | Comment | Organism | Reaction ID |
---|---|---|---|
UDP-N-acetyl-alpha-D-glucosamine = UDP-2-acetamido-2,6-dideoxy-beta-L-arabino-hex-4-ulose + H2O | catalytic mechanism of CapE, overview. Tyr164 does not act as the general base as it does in SDR enzymes displaying the SYK triad motif | Staphylococcus aureus |
Substrates | Comment Substrates | Organism | Products | Comment (Products) | Rev. | Reac. |
---|---|---|---|---|---|---|
UDP-N-acetyl-alpha-D-glucosamine | - |
Staphylococcus aureus | UDP-2-acetamido-2,6-dideoxy-beta-L-arabino-hex-4-ulose + H2O | - |
? | |
UDP-N-acetyl-alpha-D-glucosamine | CapE is a 5-inverting 4,6-dehydratase enzyme, but in the absence of downstream enzymes, CapE catalyzes an additional reaction (5-back-epimerization) affording a by-product UDP-xylo-sugar under thermodynamic control. The by-product structural analysis reveals a network of coordinated motions away from the active site governing the enzymatic activity of CapE. A second dynamic element (the latch) regulates the enzymatic chemoselectivity, second molecule of UDP-sugar is found at another binding pocket remote from the active site. The secondary binding site stabilizes the conformation of the latch and may play a role in the enzymatic regulation of CapE as observed in other enzymes. The by-product is anchored to the protein by non-covalent interactions through its UDP moiety | Staphylococcus aureus | UDP-2-acetamido-2,6-dideoxy-beta-L-arabino-hex-4-ulose + H2O | - |
? |
Synonyms | Comment | Organism |
---|---|---|
CapE | - |
Staphylococcus aureus |
Temperature Optimum [°C] | Temperature Optimum Maximum [°C] | Comment | Organism |
---|---|---|---|
37 | - |
assay at | Staphylococcus aureus |
pH Optimum Minimum | pH Optimum Maximum | Comment | Organism |
---|---|---|---|
8 | - |
assay at | Staphylococcus aureus |
Cofactor | Comment | Organism | Structure |
---|---|---|---|
additional information | the hexose ring occupies a non-catalytic conformation with respect to the coenzyme | Staphylococcus aureus | |
NADP+ | binding and binding site structure, overview. Function of Tyr164 is related to its bulkiness in the relay mechanism | Staphylococcus aureus | |
NADPH | binding and binding site structure, overview. Function of Tyr164 is related to its bulkiness in the relay mechanism | Staphylococcus aureus |
General Information | Comment | Organism |
---|---|---|
evolution | CapE belongs to a distinctive subfamily of SDR enzymes of pathogenic bacteria characterized by a singular catalytic triad displaying a Met residue (instead of the canonical Tyr residue) and a dynamic element known as the latch. Although CapE and FlaA1 afford the same product, the configuration of their active sites is different. Also, the latch region is absent in FlaA1 | Staphylococcus aureus |
metabolism | conversion of UDP-D-GlcNAc into UDP-L-FucNAc, an essential precursor of capsular polysaccharide requires three enzymes CapE, CapF, and CapG in Staphylococcus aureus. CapE yields the first intermediate of the sequential reactions catalyzed by these three enzymes | Staphylococcus aureus |
physiological function | CapE is an essential enzyme for the synthesis of capsular polysaccharide of pathogenic strains of Staphylococcus aureus | Staphylococcus aureus |