Cloned (Comment) | Organism |
---|---|
gene POMK, recombinant expression of enzyme mutants in POMK knockout cells | Danio rerio |
Crystallization (Comment) | Organism |
---|---|
purified enzyme POMK in complex with Mg2+ ions, ADP, aluminum fluoride, and the GalNAc-beta3-GlcNAc-beta4-Man trisaccharide substrate, X-ray diffraction structure determination and analysis at 2.0 A resolution | Danio rerio |
Protein Variants | Comment | Organism |
---|---|---|
A230E | site-directed mutagenesis, inactive mutant | Homo sapiens |
C203A/C244A | site-directed mutagenesis, inactive mutant | Homo sapiens |
D118A | site-directed mutagenesis, the mutant shows reduced activity compared to wild-type enzyme | Homo sapiens |
D204A | site-directed mutagenesis, the mutant shows reduced activity compared to wild-type enzyme | Homo sapiens |
D227A | site-directed mutagenesis, inactive mutant | Homo sapiens |
D229G | site-directed mutagenesis, the mutant's activity is unaltered compared to wild-type enzyme | Homo sapiens |
D229G/G122E | site-directed mutagenesis, inactive mutant | Danio rerio |
D229G/G122E | site-directed mutagenesis, the mutant shows highly reduced activity compared to wild-type enzyme | Homo sapiens |
K210A | site-directed mutagenesis, the mutation impairs the catalytic activity | Homo sapiens |
K93A | site-directed mutagenesis, the mutation of this Lys in HsPOMK to Gly completely abolished kinase activity | Homo sapiens |
K93G/S108K | site-directed mutagenesis, the catalytic activity is restored in the double mutant, which reinstalls the Lys in strand beta3. In fact, this mutant, having both the Gly-rich loop and the beta3 Lys restored, has enhanced kinase activity in vitro compared to the wild-type enzyme | Homo sapiens |
L72A | site-directed mutagenesis | Danio rerio |
additional information | disease-causing mutations, overview | Homo sapiens |
additional information | generation of POMK knockout cells | Danio rerio |
Q214A | site-directed mutagenesis, the mutant shows reduced activity compared to wild-type enzyme | Homo sapiens |
Q258R | site-directed mutagenesis, inactive mutant | Homo sapiens |
V302D | site-directed mutagenesis, inactive mutant | Homo sapiens |
Localization | Comment | Organism | GeneOntology No. | Textmining |
---|---|---|---|---|
membrane | Homo sapiens POMK (HsPOMK) contains a type II transmembrane (TM) domain and a lumenal kinase domain | Homo sapiens | 16020 | - |
Metals/Ions | Comment | Organism | Structure |
---|---|---|---|
Mg2+ | required | Homo sapiens | |
Mg2+ | required | Danio rerio |
Natural Substrates | Organism | Comment (Nat. Sub.) | Natural Products | Comment (Nat. Pro.) | Rev. | Reac. |
---|---|---|---|---|---|---|
ATP + 3-O-[N-acetyl-beta-D-galactosaminyl-(1->3)-N-acetyl-beta-D-glucosaminyl-(1->4)-alpha-D-mannosyl]-L-seryl-[protein] | Homo sapiens | - |
ADP + 3-O-[N-acetyl-beta-D-galactosaminyl-(1->3)-N-acetyl-beta-D-glucosaminyl-(1->4)-6-O-phosphono-alpha-D-mannosyl]-L-seryl-[protein] | - |
? | |
ATP + 3-O-[N-acetyl-beta-D-galactosaminyl-(1->3)-N-acetyl-beta-D-glucosaminyl-(1->4)-alpha-D-mannosyl]-L-seryl-[protein] | Danio rerio | - |
ADP + 3-O-[N-acetyl-beta-D-galactosaminyl-(1->3)-N-acetyl-beta-D-glucosaminyl-(1->4)-6-O-phosphono-alpha-D-mannosyl]-L-seryl-[protein] | - |
? | |
ATP + 3-O-[N-acetyl-beta-D-galactosaminyl-(1->3)-N-acetyl-beta-D-glucosaminyl-(1->4)-alpha-D-mannosyl]-L-threonyl-[protein] | Homo sapiens | - |
ADP + 3-O-[N-acetyl-beta-D-galactosaminyl-(1->3)-N-acetyl-beta-D-glucosaminyl-(1->4)-6-O-phosphono-alpha-D-mannosyl]-L-threonyl-[protein] | - |
? | |
ATP + 3-O-[N-acetyl-beta-D-galactosaminyl-(1->3)-N-acetyl-beta-D-glucosaminyl-(1->4)-alpha-D-mannosyl]-L-threonyl-[protein] | Danio rerio | - |
ADP + 3-O-[N-acetyl-beta-D-galactosaminyl-(1->3)-N-acetyl-beta-D-glucosaminyl-(1->4)-6-O-phosphono-alpha-D-mannosyl]-L-threonyl-[protein] | - |
? |
Organism | UniProt | Comment | Textmining |
---|---|---|---|
Danio rerio | Q5U3W1 | - |
- |
Homo sapiens | Q9H5K3 | - |
- |
Posttranslational Modification | Comment | Organism |
---|---|---|
glycoprotein | there are four potential N-linked glycosylation sites in the HsPOMK kinase domain: Asn67, Asn165, Asn220, and Asn235 | Homo sapiens |
no glycoprotein | no glycosylation site is present in DrPOMK | Danio rerio |
Substrates | Comment Substrates | Organism | Products | Comment (Products) | Rev. | Reac. |
---|---|---|---|---|---|---|
ATP + 3-O-[N-acetyl-beta-D-galactosaminyl-(1->3)-N-acetyl-beta-D-glucosaminyl-(1->4)-alpha-D-mannosyl]-L-seryl-[protein] | - |
Homo sapiens | ADP + 3-O-[N-acetyl-beta-D-galactosaminyl-(1->3)-N-acetyl-beta-D-glucosaminyl-(1->4)-6-O-phosphono-alpha-D-mannosyl]-L-seryl-[protein] | - |
? | |
ATP + 3-O-[N-acetyl-beta-D-galactosaminyl-(1->3)-N-acetyl-beta-D-glucosaminyl-(1->4)-alpha-D-mannosyl]-L-seryl-[protein] | - |
Danio rerio | ADP + 3-O-[N-acetyl-beta-D-galactosaminyl-(1->3)-N-acetyl-beta-D-glucosaminyl-(1->4)-6-O-phosphono-alpha-D-mannosyl]-L-seryl-[protein] | - |
? | |
ATP + 3-O-[N-acetyl-beta-D-galactosaminyl-(1->3)-N-acetyl-beta-D-glucosaminyl-(1->4)-alpha-D-mannosyl]-L-threonyl-[protein] | - |
Homo sapiens | ADP + 3-O-[N-acetyl-beta-D-galactosaminyl-(1->3)-N-acetyl-beta-D-glucosaminyl-(1->4)-6-O-phosphono-alpha-D-mannosyl]-L-threonyl-[protein] | - |
? | |
ATP + 3-O-[N-acetyl-beta-D-galactosaminyl-(1->3)-N-acetyl-beta-D-glucosaminyl-(1->4)-alpha-D-mannosyl]-L-threonyl-[protein] | - |
Danio rerio | ADP + 3-O-[N-acetyl-beta-D-galactosaminyl-(1->3)-N-acetyl-beta-D-glucosaminyl-(1->4)-6-O-phosphono-alpha-D-mannosyl]-L-threonyl-[protein] | - |
? | |
additional information | enzyme POMK can efficiently phosphorylate the GalNAc-beta3-GlcNAc-b4-Man trisaccharide. GalNAc-beta3-GlcNAc-beta4-Man is recognized by a surface groove, and the GalNAc-beta3-GlcNAc moiety mediates the majority of interactions with POMK | Homo sapiens | ? | - |
- |
|
additional information | enzyme POMK can efficiently phosphorylate the GalNAc-beta3-GlcNAc-beta4-Man trisaccharide. GalNAc-beta3-GlcNAc-beta4-Man is recognized by a surface groove, and the GalNAc-beta3-GlcNAc moiety mediates the majority of interactions with POMK. POMK specifically recognizes GalNAc-beta3-GlcNAc-beta4-mannose | Danio rerio | ? | - |
- |
Subunits | Comment | Organism |
---|---|---|
More | Homo sapiens POMK (HsPOMK) contains a type II transmembrane (TM) domain and a lumenal kinase domain | Homo sapiens |
Synonyms | Comment | Organism |
---|---|---|
DrPOMK | - |
Danio rerio |
HsPOMK | - |
Homo sapiens |
POMK | - |
Homo sapiens |
POMK | - |
Danio rerio |
protein O-mannose kinase | - |
Homo sapiens |
protein O-mannose kinase | - |
Danio rerio |
SGK196 | - |
Homo sapiens |
SGK196 | - |
Danio rerio |
Cofactor | Comment | Organism | Structure |
---|---|---|---|
ATP | - |
Homo sapiens | |
ATP | - |
Danio rerio |
General Information | Comment | Organism |
---|---|---|
evolution | POMK is highly conserved throughout evolution | Homo sapiens |
evolution | POMK is highly conserved throughout evolution | Danio rerio |
malfunction | loss of DrPOMK in Danio Rerio leads to disrupted muscle function | Danio rerio |
malfunction | POMK mutations cause a spectrum of congenital and limb-girdle muscular dystrophies, including the most severe presentation known as the Walker-Warburg syndrome, which is associated with brain and eye abnormalities and death in early childhood. Disease-causing mutations, overview | Homo sapiens |
metabolism | enzyme POMK plays a critical role for the biosynthesis of functional alpha-dystroglycan (alph-DG), alpha-DG is a subunit of the dystroglycan complex, and binds to basement membrane molecules such as laminin to connect the extracellular matrix with the actin cytoskeleton. alpha-DG is also a receptor for human pathogens | Homo sapiens |
metabolism | enzyme POMK plays a critical role for the biosynthesis of functional alpha-dystroglycan (alph-DG), alpha-DG is a subunit of the dystroglycan complex, and binds to basement membrane molecules such as laminin to connect the extracellular matrix with the actin cytoskeleton. alpha-DG is also a receptor for human pathogens | Danio rerio |
additional information | the structure of protein O-mannose kinase reveals a unique active site architecture. The active site of POMK is established by residues located in non-canonical positions and is stabilized by a disulfide bridge. Seven conserved Cys are present in POMK homologues, and six of them are involved in forming three pairs of disulfide bridges in DrPOMK. Cys53-Cys66 is located in a long loop in the backside of the N-lobe. Cys72-Cys139 connects helix alphaB and strand beta4. Cys201-Cys241 links the catalytic loop with the activation segment. Cys310 alone exists as a free cysteine and is buried in the C-lobe, not exposed to the solvent. DrPOMK kinase has a bilobal architecture. In POMK, a Ser (Ser106DrPOMK) occupies the position of the critical Lys72PKA in strand beta3. The critical role of this Lys in DrPOMK is instead served by Lys91_DrPOMK located at the beginning of strand beta2 that reaches into the active site and interacts with the phosphate groups of ADP. Another important Lys involved in nucleotide-binding is Lys208_DrPOMK located in helix alphaCL, it interacts with the AlF3 group that mimics the transition state gamma-phosphate of ATP | Danio rerio |
physiological function | the 'pseudokinase' SgK196 is a protein O-mannose kinase (POMK) that catalyzes an essential phosphorylation step during biosynthesis of the laminin-binding glycan on alpha-dystroglycan | Homo sapiens |
physiological function | the 'pseudokinase' SgK196 is a protein O-mannose kinase (POMK) that catalyzes an essential phosphorylation step during biosynthesis of the laminin-binding glycan on alpha-dystroglycan | Danio rerio |