Literature summary for 2.5.1.17 extracted from

St Maurice, M.; Mera, P.; Park, K.; Brunold, T.C.; Escalante-Semerena, J.C.; Rayment, I.
Structural characterization of a human-type corrinoid adenosyltransferase confirms that coenzyme B12 is synthesized through a four-coordinate intermediate (2008), Biochemistry, 47, 5755-5766.

Application

Application	Comment	Organism
medicine	ACA-mediated catalysis provides insights in molecular basis for dysfunction in methylmalonic aciduria	Limosilactobacillus reuteri

Crystallization (Commentary)

Crystallization (Comment)	Organism
trimer of three independent five-helix bundles, active sites at the interface between adjacent monomers, no significant structural changes accompany catalysis, precatalytic complex with ATP: cob(II)alamin (PDB: 3CI1, four-coordinate, base-off cob(II)alamin intermediate, enzyme with fully ordered six C-terminal residues and potassium ion in active site), complex with tripolyphosphate: adenosylcobalamin (PDB: 3CI3, partially occupied with five-coordinate adenosylcobalamin), precatalytic complex with ATP: cob(II)inamide (PDB: 3CI4, cob(II)inamide-binding structurally indistinguishable from cob(II)alamin-binding), binding of cobalamin and cobinamide (lacking dimethylbenzimidazole moiety) in identical positions and orientation, space group R3, one molecule in asymmetric unit, unit cell parameters: a: 67.8-68, b: 67.8-68, c: 110.9-111.3, beta: 90°, molecular replacement using PDB: 2NT8 as model; vapour-diffusion with tag-cleaved protein solution (18-22 mg/ml, in presence of hydroxycobalamin and/or adenosylcobalamin or dicyanocobinamide, ATP etc.) and reservoir solution (10-13% (w/v) PEG 8000, pH 6), cubic crystals, crystallisation under anoxic conditions in presence of flavin-dependent reducing system	Limosilactobacillus reuteri

Crystallization (Comment)

Organism

trimer of three independent five-helix bundles, active sites at the interface between adjacent monomers, no significant structural changes accompany catalysis, precatalytic complex with ATP: cob(II)alamin (PDB: 3CI1, four-coordinate, base-off cob(II)alamin intermediate, enzyme with fully ordered six C-terminal residues and potassium ion in active site), complex with tripolyphosphate: adenosylcobalamin (PDB: 3CI3, partially occupied with five-coordinate adenosylcobalamin), precatalytic complex with ATP: cob(II)inamide (PDB: 3CI4, cob(II)inamide-binding structurally indistinguishable from cob(II)alamin-binding), binding of cobalamin and cobinamide (lacking dimethylbenzimidazole moiety) in identical positions and orientation, space group R3, one molecule in asymmetric unit, unit cell parameters: a: 67.8-68, b: 67.8-68, c: 110.9-111.3, beta: 90°, molecular replacement using PDB: 2NT8 as model; vapour-diffusion with tag-cleaved protein solution (18-22 mg/ml, in presence of hydroxycobalamin and/or adenosylcobalamin or dicyanocobinamide, ATP etc.) and reservoir solution (10-13% (w/v) PEG 8000, pH 6), cubic crystals, crystallisation under anoxic conditions in presence of flavin-dependent reducing system

Limosilactobacillus reuteri

Inhibitors

Inhibitors	Comment	Organism	Structure
cobinamide	substrate inhibition	Limosilactobacillus reuteri

Organism

Organism	UniProt	Comment	Textmining
Limosilactobacillus reuteri	-	-	-

Reaction

Reaction	Comment	Organism	Reaction ID
2 ATP + 2 cob(II)yrinic acid a,c-diamide + a reduced flavoprotein = 2 triphosphate + 2 adenosylcob(III)yrinic acid a,c-diamide + an oxidized flavoprotein	not yet confimed	Limosilactobacillus reuteri	a

Specific Activity [micromol/min/mg]

Specific Activity Minimum [µmol/min/mg]	Specific Activity Maximum [µmol/min/mg]	Comment	Organism
0.0005	-	in presence of 1 mM ATP, 20 mM NADH, 2 mM FMN, 0.5 mM hydroxycobalamin and NAD(P)H: flavin oxidoreductase, 1.5 mM MgCl2, 100 mM KCl, pH 6	Limosilactobacillus reuteri

Substrates and Products (Substrate)

Substrates	Comment Substrates	Organism	Products	Comment (Products)	Rev.	Reac.
ATP + hydroxycobalamin	coenzyme B12 synthesis from vitamin B12, dimethylbenzimidazole arm of vitamin B12 plays no role in substrate positioning, corrinoid adenosylation assay: anaerobic, pH 6, 25°C, 1 or 2 mM FMN, 10 or 20 mM NADH, NAD(P)H: flavin oxidoreductase, 2 h incubation for complete reduction of hydroxycobalamin to cob(II)alamin before initiation of adenosyltransfer	Limosilactobacillus reuteri	tripolyphosphate + adenosylcobalamin + H2O	measuring difference in absorbance by adenosylcobalamin at 525 nm	?

Synonyms

Synonyms	Comment	Organism
human-type ATP: cob(I)alamin adenosyltransferase	-	Limosilactobacillus reuteri
LrPduO	-	Limosilactobacillus reuteri
PduO-type ACA	-	Limosilactobacillus reuteri

Turnover Number [1/s]

Turnover Number Minimum [1/s]	Turnover Number Maximum [1/s]	Substrate	Comment	Organism	Structure
additional information	-	additional information	adenosylation of cobalamin and cobinamide (lacking dimethylbenzimidazole moiety) at similar rates	Limosilactobacillus reuteri