Enzymes
| UniProtKB help_outline | 5 proteins |
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- Name help_outline precorrin-8X Identifier CHEBI:58581 Charge -7 Formula C45H53N4O14 InChIKeyhelp_outline IGCZFSMEIXUSJY-FKUSVXTQSA-G SMILEShelp_outline CC1C2=N[C@@](C)(CC3=N\C(=C(C)/C4=N[C@@](C)([C@@H]5N=C1[C@](C)(CCC([O-])=O)[C@H]5CC([O-])=O)[C@@](C)(CC([O-])=O)[C@@H]4CCC([O-])=O)[C@@](C)(CC([O-])=O)[C@@H]3CCC([O-])=O)C(C)=C2CCC([O-])=O 2D coordinates Mol file for the small molecule Search links Involved in 3 reaction(s) Find molecules that contain or resemble this structure Find proteins in UniProtKB for this molecule
- Name help_outline H+ Identifier CHEBI:15378 Charge 1 Formula H InChIKeyhelp_outline GPRLSGONYQIRFK-UHFFFAOYSA-N SMILEShelp_outline [H+] 2D coordinates Mol file for the small molecule Search links Involved in 9,836 reaction(s) Find molecules that contain or resemble this structure Find proteins in UniProtKB for this molecule
- Name help_outline hydrogenobyrinate Identifier CHEBI:77873 Charge -4 Formula C45H56N4O14 InChIKeyhelp_outline MYMATQFDUQLSCD-IPUCCYEASA-J SMILEShelp_outline C\C1=C2\N[C@@](C)([C@@H]3[NH+]=C(\C(C)=C4/[NH+]=C(/C=C5\[NH+]=C1[C@@](C)(CC([O-])=O)[C@@H]5CCC([O-])=O)C(C)(C)[C@@H]4CCC([O-])=O)[C@](C)(CCC([O-])=O)[C@H]3CC([O-])=O)[C@@](C)(CC([O-])=O)[C@@H]2CCC([O-])=O 2D coordinates Mol file for the small molecule Search links Involved in 2 reaction(s) Find molecules that contain or resemble this structure Find proteins in UniProtKB for this molecule
Cross-references
| RHEA:22512 | RHEA:22513 | RHEA:22514 | RHEA:22515 | |
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| Reaction direction help_outline | undefined | left-to-right | right-to-left | bidirectional |
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Publications
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Crystal structure of precorrin-8x methyl mutase.
Shipman L.W., Li D., Roessner C.A., Scott A.I., Sacchettini J.C.
<h4>Background</h4>The crystal structure of precorrin-8x methyl mutase (CobH), an enzyme of the aerobic pathway to vitamin B12, provides evidence that the mechanism for methyl migration can plausibly be regarded as an allowed [1,5]-sigmatropic shift of a methyl group from C-11 to C-12 at the C rin ... >> More
<h4>Background</h4>The crystal structure of precorrin-8x methyl mutase (CobH), an enzyme of the aerobic pathway to vitamin B12, provides evidence that the mechanism for methyl migration can plausibly be regarded as an allowed [1,5]-sigmatropic shift of a methyl group from C-11 to C-12 at the C ring of precorrin-8x to afford hydrogenobyrinic acid.<h4>Results</h4>The dimeric structure of CobH creates a set of shared active sites that readily discriminate between different tautomers of precorrin-8x and select a discrete tautomer for sigmatropic rearrangement. The active site contains a strictly conserved histidine residue close to the site of methyl migration in ring C of the substrate.<h4>Conclusion</h4>Analysis of the structure with bound product suggests that the [1,5]-sigmatropic shift proceeds by protonation of the ring C nitrogen, leading to subsequent methyl migration. << Less
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The final step in the biosynthesis of hydrogenobyrinic acid is catalyzed by the cobH gene product with precorrin-8x as the substrate.
Thibaut D., Couder M., Famechon A., Debussche L., Cameron B., Crouzet J., Blanche F.
The final enzymatic reaction in the conversion of precorrin-6x to hydrogenobyrinic acid by cell-free protein preparations from Pseudomonas denitrificans was shown to be inhibited by hydrogenobyrinic acid. Use was made of this property to prepare the last biosynthetic precursor of hydrogenobyrinic ... >> More
The final enzymatic reaction in the conversion of precorrin-6x to hydrogenobyrinic acid by cell-free protein preparations from Pseudomonas denitrificans was shown to be inhibited by hydrogenobyrinic acid. Use was made of this property to prepare the last biosynthetic precursor of hydrogenobyrinic acid, named precorrin-8x. Double-labeling experiments, mass spectrometry, and UV-visible light spectroscopy studies established that precorrin-8x was at the oxidation level of a corrin and differed from precorrin-6x by two additional methyl groups (presumably at C-5 and C-15) and decarboxylation of the acetic acid side chain at C-12. Precorrin-8x was not a corrin but had the same mass as hydrogenobyrinic acid, thus showing that this latter compound is synthesized from the former by a rearrangement. The enzyme catalyzing this rearrangement was purified 80-fold to homogeneity from a recombinant strain of P. denitrificans, sequenced at its N terminus, and shown to be encoded by the cobH gene. It was identical to the previously described hydrogenobyrinic acid-binding protein (F. Blanche, D. Thibaut, D. Frechet, M. Vuilhorgne, J. Crouzet, B. Cameron, G. Müller, K. Hlineny, U. Traub-Eberhard, and M. Zboron, Angew. Chem. Int. Ed. Engl. 29:884-886, 1990). This enzyme had a Km of 0.91 +/-0.04 microM and a Vmax of 230 nmol h-1 mg-1 at pH 7.7 and was competitively inhibited by hydrogenobyrinic acid with a Ki of 0.17 +/-0.01 microM. It is proposed that the cobH gene product is a mutase which transfers the methyl group from C-11 to C-12. << Less
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Genetic and sequence analysis of an 8.7-kilobase Pseudomonas denitrificans fragment carrying eight genes involved in transformation of precorrin-2 to cobyrinic acid.
Crouzet J., Cameron B., Cauchois L., Rigault S., Rouyez M.-C., Blanche F., Thibaut D., Debussche L.
A 8.7-kilobase DNA fragment carrying Pseudomonas denitrificans cob genes has been sequenced. The nucleotide sequence and the genetic analysis revealed that this fragment carries eight different cob genes (cobF to cobM). Six of these genes have the characteristics of translationally coupled genes. ... >> More
A 8.7-kilobase DNA fragment carrying Pseudomonas denitrificans cob genes has been sequenced. The nucleotide sequence and the genetic analysis revealed that this fragment carries eight different cob genes (cobF to cobM). Six of these genes have the characteristics of translationally coupled genes. cobI has been identified as S-adenosyl-L-methionine (SAM):precorrin-2 methyltransferase structural gene because the encoded protein has the same NH2 terminus and molecular weight as those of the purified enzyme. From protein homology with CobA and CobI, two SAM-dependent methyltransferases of the cobalamin pathway, it is proposed that cobF, cobJ, cobL, and cobM code for other methyltransferases involved in the cobalamin pathway. In addition, purified CobF protein has affinity for SAM, as expected for a SAM-dependent methyltransferase. Accumulation of cobalamin precursors in Agrobacterium tumefaciens mutants complemented by any of these eight genes suggest that, apart from cobI, whose function is identified, the products of all these genes are implicated in the conversion of precorrin-3 into cobyrinic acid. << Less
J. Bacteriol. 172:5980-5990(1990) [PubMed] [EuropePMC]
This publication is cited by 1 other entry.