Activating Compound | Comment | Organism | Structure |
---|---|---|---|
additional information | no activation by EDTA, and 1 mM DTT | Neisseria meningitidis serogroup A / serotype 4A | |
UDP-GlcNAc | allosteric activator, absolutely required for their UDP-ManNAc 2-epimerization catalytic activity, activates recombinant His6-tagged enzyme NmSacA | Neisseria meningitidis serogroup A / serotype 4A | |
UDP-N-acetyl-alpha-D-glucosamine | activates the recombinant enzyme, UDP-GlcNAc is able to activate the epimerization process in a dose-dependent manner | Neisseria meningitidis serogroup A /serotype 4A |
Cloned (Comment) | Organism |
---|---|
gene sacA, encoded in the serogroup A cps operon, sequence comparisons, recombinant overexpression of C-terminally His6-tagged recombinant NmSacA in Escherichia coli strain BL21(DE3) | Neisseria meningitidis serogroup A / serotype 4A |
gene sacA, recombinant expression of C-terminally His6-tagged enzyme NmSacA in Escherichia coli strain BL21(DE3) | Neisseria meningitidis serogroup A /serotype 4A |
Inhibitors | Comment | Organism | Structure |
---|---|---|---|
2-acetamidoglucal | - |
Neisseria meningitidis serogroup A / serotype 4A | |
2-acetamidoglucal | recombinant enzyme | Neisseria meningitidis serogroup A /serotype 4A | |
Ca2+ | - |
Neisseria meningitidis serogroup A / serotype 4A | |
Ca2+ | slight inhibition at 10 mM | Neisseria meningitidis serogroup A /serotype 4A | |
Co2+ | strong inhibition at 10 mM | Neisseria meningitidis serogroup A /serotype 4A | |
Cu2+ | - |
Neisseria meningitidis serogroup A / serotype 4A | |
Cu2+ | slight inhibition at 10 mM | Neisseria meningitidis serogroup A /serotype 4A | |
Mg2+ | - |
Neisseria meningitidis serogroup A / serotype 4A | |
Mg2+ | slight inhibition at 10 mM | Neisseria meningitidis serogroup A /serotype 4A | |
Mn2+ | complete inhibition at 10 mM, the epimerase and the activity cannot be rescued by subsequent addition of EDTA | Neisseria meningitidis serogroup A /serotype 4A | |
Mn2+ | leads to enzyme precipitation at 10 mM | Neisseria meningitidis serogroup A / serotype 4A | |
additional information | both 2-acetamidoglucal and UDP show competitive inhibitory effects for the UDP-ManNAc 2-epimerization of NmSacA-His6. No inhibition by EDTA, and 1 mM DTT | Neisseria meningitidis serogroup A / serotype 4A | |
Ni2+ | - |
Neisseria meningitidis serogroup A / serotype 4A | |
Ni2+ | slight inhibition at 10 mM | Neisseria meningitidis serogroup A /serotype 4A | |
UDP | - |
Neisseria meningitidis serogroup A / serotype 4A | |
UDP | recombinant enzyme | Neisseria meningitidis serogroup A /serotype 4A | |
Zn2+ | complete inhibition at 10 mM, the epimerase and the activity cannot be rescued by subsequent addition of EDTA | Neisseria meningitidis serogroup A /serotype 4A | |
Zn2+ | leads to enzyme precipitation at 10 mM | Neisseria meningitidis serogroup A / serotype 4A |
KM Value [mM] | KM Value Maximum [mM] | Substrate | Comment | Organism | Structure |
---|---|---|---|---|---|
3.6 | - |
UDP-N-acetyl-alpha-D-glucosamine | pH 8.5, 37°C, recombinant enzyme | Neisseria meningitidis serogroup A / serotype 4A | |
5.2 | - |
UDP-N-acetyl-alpha-D-mannosamine | pH 8.5, 37°C, recombinant enzyme | Neisseria meningitidis serogroup A / serotype 4A |
Metals/Ions | Comment | Organism | Structure |
---|---|---|---|
additional information | the 2-epimerase activity of NmSacA-His6 is not dependent on the addition of an external divalent metal ion, Li+ and EDTA have no effect on enzyme activity | Neisseria meningitidis serogroup A / serotype 4A | |
additional information | the 2-epimerase activity of NmSacA-His6 is not dependent on the addition of an external divalent metal ion. No effect by 10 mM of EDTA and Li+, poor effect by 1 mM DTT | Neisseria meningitidis serogroup A /serotype 4A |
Natural Substrates | Organism | Comment (Nat. Sub.) | Natural Products | Comment (Nat. Pro.) | Rev. | Reac. |
---|---|---|---|---|---|---|
UDP-N-acetyl-alpha-D-glucosamine | Neisseria meningitidis serogroup A / serotype 4A | - |
UDP-N-acetyl-alpha-D-mannosamine | - |
r | |
UDP-N-acetyl-alpha-D-glucosamine | Neisseria meningitidis serogroup A /serotype 4A | - |
UDP-N-acetyl-alpha-D-mannosamine | - |
r | |
UDP-N-acetyl-alpha-D-glucosamine | Neisseria meningitidis serogroup A / serotype 4A Z2491 | - |
UDP-N-acetyl-alpha-D-mannosamine | - |
r | |
UDP-N-acetyl-alpha-D-glucosamine | Neisseria meningitidis serogroup A /serotype 4A Z2491 | - |
UDP-N-acetyl-alpha-D-mannosamine | - |
r |
Organism | UniProt | Comment | Textmining |
---|---|---|---|
Neisseria meningitidis serogroup A / serotype 4A | A0A0U1RGY0 | - |
- |
Neisseria meningitidis serogroup A / serotype 4A Z2491 | A0A0U1RGY0 | - |
- |
Neisseria meningitidis serogroup A /serotype 4A | A0A0U1RGY0 | - |
- |
Neisseria meningitidis serogroup A /serotype 4A Z2491 | A0A0U1RGY0 | - |
- |
Purification (Comment) | Organism |
---|---|
recombinant C-terminally His6-tagged enzyme NmSacA from Escherichia coli strain BL21(DE3) by nickel affinity chromatography | Neisseria meningitidis serogroup A /serotype 4A |
recombinant C-terminally His6-tagged NmSacA from Escherichia coli strain BL21(DE3) by nickel affinity chromatography | Neisseria meningitidis serogroup A / serotype 4A |
Substrates | Comment Substrates | Organism | Products | Comment (Products) | Rev. | Reac. |
---|---|---|---|---|---|---|
dihydropyrimidine-2,4(1H,3H)-dione-alpha-D-ribofuranosyl-5'-diphospho-2-acetamido-2-deoxy-alpha-D-mannopyranoside | - |
Neisseria meningitidis serogroup A / serotype 4A | ? | - |
? | |
dihydropyrimidine-2,4(1H,3H)-dione-alpha-D-ribofuranosyl-5'-diphospho-2-acetamido-2-deoxy-alpha-D-mannopyranoside | - |
Neisseria meningitidis serogroup A / serotype 4A Z2491 | ? | - |
? | |
additional information | substrate specificity, overview. Recombinant His6-tagged NmSacA-His6 can tolerate several chemoenzymatically synthesized UDP-ManNAc derivatives as substrates in the absence of UDP-GlcNAc although its activity is much lower than with non-modified UDP-ManNAc. Homology modeling and molecular docking. The formation of UDP-GlcNAc or UDP-ManNAc is not observed by incubating NmSacA-His6 with 2-acetamidoglucal and UDP in contrast to the serogroup B enzyme. No enzyme activity with UDP-mannose, UDP-ManF, UDP-ManN3, UDP-ManNH2, uridine 5'-diphospho-2-butyramido-2-deoxy-alpha-D-mannopyranoside, uridine 5'-diphospho-2-azidoacetamido-2-deoxy-alpha-D-mannopyranoside, uridine 5'-diphospho-2-phenylacetamido-2-deoxy-alpha-D-mannopyranoside, dihydropyrimidine-2, 4(1H,3H)-dione-alpha-D-ribofuranosyl-5'-diphospho-2-azidoxyacetamido-2-deoxy-alpha-D-mannopyranoside, and uridine 5'-diphospho-2-azidoacetamido-2-deoxy-alpha-D-glucopyranoside, docking study | Neisseria meningitidis serogroup A / serotype 4A | ? | - |
? | |
additional information | the recombinnat enzyme His6-tagged NmSacA tolerates several chemoenzymatically synthesized UDP-ManNAc derivatives as substrates although its activity is much lower than with non-modified UDP-ManNAc, substrate specificity, overview | Neisseria meningitidis serogroup A /serotype 4A | ? | - |
? | |
additional information | substrate specificity, overview. Recombinant His6-tagged NmSacA-His6 can tolerate several chemoenzymatically synthesized UDP-ManNAc derivatives as substrates in the absence of UDP-GlcNAc although its activity is much lower than with non-modified UDP-ManNAc. Homology modeling and molecular docking. The formation of UDP-GlcNAc or UDP-ManNAc is not observed by incubating NmSacA-His6 with 2-acetamidoglucal and UDP in contrast to the serogroup B enzyme. No enzyme activity with UDP-mannose, UDP-ManF, UDP-ManN3, UDP-ManNH2, uridine 5'-diphospho-2-butyramido-2-deoxy-alpha-D-mannopyranoside, uridine 5'-diphospho-2-azidoacetamido-2-deoxy-alpha-D-mannopyranoside, uridine 5'-diphospho-2-phenylacetamido-2-deoxy-alpha-D-mannopyranoside, dihydropyrimidine-2, 4(1H,3H)-dione-alpha-D-ribofuranosyl-5'-diphospho-2-azidoxyacetamido-2-deoxy-alpha-D-mannopyranoside, and uridine 5'-diphospho-2-azidoacetamido-2-deoxy-alpha-D-glucopyranoside, docking study | Neisseria meningitidis serogroup A / serotype 4A Z2491 | ? | - |
? | |
additional information | the recombinnat enzyme His6-tagged NmSacA tolerates several chemoenzymatically synthesized UDP-ManNAc derivatives as substrates although its activity is much lower than with non-modified UDP-ManNAc, substrate specificity, overview | Neisseria meningitidis serogroup A /serotype 4A Z2491 | ? | - |
? | |
UDP-N-acetyl-alpha-D-glucosamine | - |
Neisseria meningitidis serogroup A / serotype 4A | UDP-N-acetyl-alpha-D-mannosamine | - |
r | |
UDP-N-acetyl-alpha-D-glucosamine | - |
Neisseria meningitidis serogroup A /serotype 4A | UDP-N-acetyl-alpha-D-mannosamine | - |
r | |
UDP-N-acetyl-alpha-D-glucosamine | interconversion | Neisseria meningitidis serogroup A /serotype 4A | UDP-N-acetyl-alpha-D-mannosamine | - |
r | |
UDP-N-acetyl-alpha-D-glucosamine | - |
Neisseria meningitidis serogroup A / serotype 4A Z2491 | UDP-N-acetyl-alpha-D-mannosamine | - |
r | |
UDP-N-acetyl-alpha-D-glucosamine | - |
Neisseria meningitidis serogroup A /serotype 4A Z2491 | UDP-N-acetyl-alpha-D-mannosamine | - |
r | |
UDP-N-acetyl-alpha-D-glucosamine | interconversion | Neisseria meningitidis serogroup A /serotype 4A Z2491 | UDP-N-acetyl-alpha-D-mannosamine | - |
r | |
UDP-N-acetyl-alpha-D-mannosamine | - |
Neisseria meningitidis serogroup A / serotype 4A | UDP-N-acetyl-alpha-D-glucosamine | - |
r | |
UDP-N-acetyl-alpha-D-mannosamine | interconversion | Neisseria meningitidis serogroup A /serotype 4A | UDP-N-acetyl-alpha-D-glucosamine | - |
r | |
UDP-N-acetyl-alpha-D-mannosamine | - |
Neisseria meningitidis serogroup A / serotype 4A Z2491 | UDP-N-acetyl-alpha-D-glucosamine | - |
r | |
UDP-N-acetyl-alpha-D-mannosamine | interconversion | Neisseria meningitidis serogroup A /serotype 4A Z2491 | UDP-N-acetyl-alpha-D-glucosamine | - |
r | |
uridine 5'-diphospho-2-hydroxyacetamido-2-deoxy-alpha-D-mannopyranoside | - |
Neisseria meningitidis serogroup A / serotype 4A | ? | - |
? | |
uridine 5'-diphospho-2-hydroxyacetamido-2-deoxy-alpha-D-mannopyranoside | - |
Neisseria meningitidis serogroup A / serotype 4A Z2491 | ? | - |
? | |
uridine 5'-diphospho-2-propionamido-2-deoxy-alpha-D-mannopyranoside | - |
Neisseria meningitidis serogroup A / serotype 4A | ? | - |
? | |
uridine 5'-diphospho-N-trifluoroaceto-2-deoxy-alpha-D-mannopyranoside | - |
Neisseria meningitidis serogroup A / serotype 4A | ? | - |
? |
Subunits | Comment | Organism |
---|---|---|
? | x * 43000, recombinant His6-tagged enzyme, SDS-PAGE | Neisseria meningitidis serogroup A /serotype 4A |
? | x * 43000, recombinant His6-tagged NmSacA, SDS-PAGE | Neisseria meningitidis serogroup A / serotype 4A |
Synonyms | Comment | Organism |
---|---|---|
NmSacA | - |
Neisseria meningitidis serogroup A / serotype 4A |
NmSacA | - |
Neisseria meningitidis serogroup A /serotype 4A |
non-hydrolyzing Neisseria meningitidis serogroup A UDP-GlcNAc 2-epimerase | - |
Neisseria meningitidis serogroup A /serotype 4A |
non-hydrolyzing Neisseria meningitidis serogroup A UDP-N-acetylglucosamine 2-epimerase | - |
Neisseria meningitidis serogroup A /serotype 4A |
non-hydrolyzing UDP-GlcNAc 2-epimerase | - |
Neisseria meningitidis serogroup A / serotype 4A |
non-hydrolyzing UDP-GlcNAc 2-epimerase | - |
Neisseria meningitidis serogroup A /serotype 4A |
non-hydrolyzing UDP-N-acetylglucosamine 2-epimerase | - |
Neisseria meningitidis serogroup A / serotype 4A |
non-hydrolyzing uridine 5'-diphosphate-N-acetylglucosamine 2-epimerase | - |
Neisseria meningitidis serogroup A / serotype 4A |
SacA | - |
Neisseria meningitidis serogroup A /serotype 4A |
SacA | - |
Neisseria meningitidis serogroup A / serotype 4A |
UDP-GlcNAc 2-epimerase | - |
Neisseria meningitidis serogroup A / serotype 4A |
Temperature Optimum [°C] | Temperature Optimum Maximum [°C] | Comment | Organism |
---|---|---|---|
37 | - |
assay at | Neisseria meningitidis serogroup A / serotype 4A |
Turnover Number Minimum [1/s] | Turnover Number Maximum [1/s] | Substrate | Comment | Organism | Structure |
---|---|---|---|---|---|
31 | - |
UDP-N-acetyl-alpha-D-glucosamine | pH 8.5, 37°C, recombinant enzyme | Neisseria meningitidis serogroup A / serotype 4A | |
52 | - |
UDP-N-acetyl-alpha-D-mannosamine | pH 8.5, 37°C, recombinant enzyme | Neisseria meningitidis serogroup A / serotype 4A |
pH Optimum Minimum | pH Optimum Maximum | Comment | Organism |
---|---|---|---|
8 | 9 | - |
Neisseria meningitidis serogroup A / serotype 4A |
8 | 9 | recombinant enzyme | Neisseria meningitidis serogroup A /serotype 4A |
pH Minimum | pH Maximum | Comment | Organism |
---|---|---|---|
6 | 11 | activity range, recombinant enzyme | Neisseria meningitidis serogroup A /serotype 4A |
6 | 11 | activity range with high activity | Neisseria meningitidis serogroup A / serotype 4A |
Ki Value [mM] | Ki Value maximum [mM] | Inhibitor | Comment | Organism | Structure |
---|---|---|---|---|---|
0.8 | - |
UDP | pH 8.5, 37°C, recombinant enzyme | Neisseria meningitidis serogroup A / serotype 4A | |
14 | - |
2-acetamidoglucal | pH 8.5, 37°C, recombinant enzyme | Neisseria meningitidis serogroup A / serotype 4A |
General Information | Comment | Organism |
---|---|---|
additional information | of the six major disease-causing Neisseria meningitidis serogroups, only serogroups A and X produce capsular polysaccharides (CPSs) that do not have N-acetylneuraminic acid (Neu5Ac, sialic acid is a more general term) residues. Unlike the CPSs of serogroups B and C which are homopolymers of Neu5Ac with alpha2-8- and alpha2-9-linkages respectively, or serogroups W-135 and Y CPSs which are heteropolymers of [-6Gal/Glcalpha1-4Neu5Acalpha2-]n with alternating Neu5Ac and Gal/Glc as disaccharide repeating units, the CPS of serogroup A is a homopolymer of [-6ManNAcalpha1-phosphate-]n. Correspondingly, the genetic organization for serogroup A capsule is different from those for serogroups B, C, W-135, and Y | Neisseria meningitidis serogroup A / serotype 4A |
additional information | homology modeling and molecular docking reveal structural determinants of NmSacA substrate specificity. Disulfide bond formation is not required for the epimerase activity of NmSacA-His6 | Neisseria meningitidis serogroup A /serotype 4A |
physiological function | SacA is proposed to be involved in the first step in serogroup A capsular polysaccharides (CPS) biosynthetic pathway and is critical for serogroup A CPS biosynthesis. It catalyzes the interconversion between UDP-GlcNAc and UDP-ManNAc. This epimerization process is independent of nicotinamide adenine dinucleotide oxidized form (NAD+) and is critical for synthesizing bacterial ManNAc-containing CPSs | Neisseria meningitidis serogroup A / serotype 4A |
physiological function | Neisseria meningitidis serogroup A non-hydrolyzing UDP-GlcNAc 2-epimerase (NmSacA) catalyzes the interconversion between UDP-GlcNAc and uridine 5?-diphosphate-N-acetylmannosamine (UDP-ManNAc). It is a key enzyme involved in the biosynthesis of the capsular polysaccharide [-6ManNAc?1-phosphate-]n of N. meningitidis serogroup A, one of the six serogroups (A, B, C, W-135, X, and Y) that account for most cases of Neisseria meningitidis-caused bacterial septicemia and meningitis | Neisseria meningitidis serogroup A /serotype 4A |
kcat/KM Value [1/mMs-1] | kcat/KM Value Maximum [1/mMs-1] | Substrate | Comment | Organism | Structure |
---|---|---|---|---|---|
8.6 | - |
UDP-N-acetyl-alpha-D-mannosamine | pH 8.5, 37°C, recombinant enzyme | Neisseria meningitidis serogroup A / serotype 4A | |
10 | - |
UDP-N-acetyl-alpha-D-glucosamine | pH 8.5, 37°C, recombinant enzyme | Neisseria meningitidis serogroup A / serotype 4A |