DCAKD

Model summary

A soluble human kinase that completes coenzyme A biosynthesis by using ATP to phosphorylate dephospho-CoA, thereby supplying coenzyme A for central acyl-transfer reactions. Its nucleotide-binding core drives phosphoryl transfer, and its propensity for protein interactions likely organizes pathway enzymes into transient assemblies. By operating near membrane-associated metabolic hubs, it channels acyl-group flux and supports energy and lipid metabolism despite lacking transmembrane segments.

Predicted Gene Ontology terms

1. 01

   I begin with the InterPro architecture.

   The sequence is fully encompassed by IPR027417 (P-loop containing nucleoside triphosphate hydrolase homologous superfamily, residues 1–203), indicating a classical NTP-binding fold that stabilizes phosphate groups and coordinates divalent cations to catalyze phosphoryl transfer. This scaffold is reinforced and specialized by IPR001977 (Dephospho-CoA kinase family, residues 1–207), which defines the enzyme class that converts dephospho-CoA to coenzyme A via ATP-dependent phosphorylation. The coextensive coverage of both signatures across essentially the entire polypeptide establishes a soluble, ATP-driven kinase core that binds nucleotides and positions the dephospho-CoA substrate for in-line transfer to the 3′-phosphate of the adenosine moiety. This architecture causes ATP binding and hydrolysis-coupled chemistry typical of P-loop NTPases and assigns the catalytic identity of a dephospho-CoA kinase.

2. 02

   From this domain logic, the molecular function resolves into two facets.

   First, the P-loop NTPase core and dephospho-CoA kinase family membership specify an ATP-dependent phosphotransferase that executes the terminal step of the coenzyme A pathway. Second, the absence of transmembrane segments and the soluble kinase fold imply that multivalent contacts with other proteins are used for regulation and assembly, consistent with GO:0005515 protein binding. Such binding capacity is expected for a pathway terminal enzyme that often forms transient complexes with upstream and downstream biosynthetic partners.

3. 03

   The catalytic role directly situates the protein in coenzyme A biogenesis.

   By generating coenzyme A, it completes the pathway formalized as GO:0015937 coenzyme A biosynthetic process. This terminal step is pivotal because coenzyme A is required for acyl transfer reactions in central metabolism and lipid synthesis; thus, the enzyme’s activity feeds into mitochondrial energy production and cytosolic acylation pathways.

4. 04

   Cellular placement follows from the soluble kinase architecture and pathway context.

   The lack of transmembrane domains supports a soluble pool, yet the functional coupling of acetyl-CoA production and utilization frequently anchors CoA pathway enzymes to intracellular membranes. This creates a mechanistic rationale for GO:0016020 membrane: transient or peripheral association with membrane surfaces can concentrate pathway flux near sites of acyl-group exchange and energy transduction. Such membrane-proximal positioning can be achieved through protein-mediated tethering rather than integral membrane insertion, aligning with a soluble enzyme that operates at membrane interfaces.

5. 05

   Mechanistically, the enzyme likely binds ATP and Mg2+ within the P-loop pocket, aligns dephospho-CoA in the family-defined active site, and executes a phosphoryl transfer that yields coenzyme A and ADP.

   It probably forms assemblies with other CoA-pathway enzymes to channel intermediates and with membrane-associated metabolic hubs, explaining both its protein-binding propensity and membrane association. I hypothesize interactions with upstream CoA-biosynthetic enzymes and with membrane-proximal acetyl-CoA–utilizing complexes, enabling efficient substrate handoff and spatial control of acyl-group flux.