Publications

• An enzyme-trap approach allows isolation of intermediates in cobalamin biosynthesis.

  Deery E., Schroeder S., Lawrence A.D., Taylor S.L., Seyedarabi A., Waterman J., Wilson K.S., Brown D., Geeves M.A., Howard M.J., Pickersgill R.W., Warren M.J.

  The biosynthesis of many vitamins and coenzymes has often proven difficult to elucidate owing to a combination of low abundance and kinetic lability of the pathway intermediates. Through a serial reconstruction of the cobalamin (vitamin B(12)) pathway in Escherichia coli and by His tagging the ter ... >> More

  The biosynthesis of many vitamins and coenzymes has often proven difficult to elucidate owing to a combination of low abundance and kinetic lability of the pathway intermediates. Through a serial reconstruction of the cobalamin (vitamin B(12)) pathway in Escherichia coli and by His tagging the terminal enzyme in the reaction sequence, we have observed that many unstable intermediates can be isolated as tightly bound enzyme-product complexes. Together, these approaches have been used to extract intermediates between precorrin-4 and hydrogenobyrinic acid in their free acid form and permitted the delineation of the overall reaction catalyzed by CobL, including the formal elucidation of precorrin-7 as a metabolite. Furthermore, a substrate-carrier protein, CobE, that can also be used to stabilize some of the transient metabolic intermediates and enhance their onward transformation, has been identified. The tight association of pathway intermediates with enzymes provides evidence for a form of metabolite channeling. << Less

  Nat Chem Biol 8:933-940(2012) [PubMed] [EuropePMC]

  This publication is cited by 2 other entries.

• Biosynthesis of vitamin B12 in Pseudomonas denitrificans: the biosynthetic sequence from precorrin-6y to precorrin-8x is catalyzed by the cobL gene product.

  Blanche F., Famechon A., Thibaut D., Debussche L., Cameron B., Crouzet J.

  A protein catalyzing methylation at C-5 and C-15 and decarboxylation of the acetic acid side chain at C-12 on precorrin-6y to yield precorrin-8x was purified to homogeneity from a recombinant strain of Pseudomonas denitrificans. It was sequenced at the N terminus and shown to be encoded by the cob ... >> More

  A protein catalyzing methylation at C-5 and C-15 and decarboxylation of the acetic acid side chain at C-12 on precorrin-6y to yield precorrin-8x was purified to homogeneity from a recombinant strain of Pseudomonas denitrificans. It was sequenced at the N terminus and shown to be encoded by the cobL gene. << Less

  J. Bacteriol. 174:1050-1052(1992) [PubMed] [EuropePMC]

• The crystal structure of MT0146/CbiT suggests that the putative precorrin-8w decarboxylase is a methyltransferase.

  Keller J.P., Smith P.M., Benach J., Christendat D., deTitta G.T., Hunt J.F.

  The CbiT and CbiE enzymes participate in the biosynthesis of vitamin B12. They are fused together in some organisms to form a protein called CobL, which catalyzes two methylations and one decarboxylation on a precorrin intermediate. Because CbiE has sequence homology to canonical precorrin methylt ... >> More

  The CbiT and CbiE enzymes participate in the biosynthesis of vitamin B12. They are fused together in some organisms to form a protein called CobL, which catalyzes two methylations and one decarboxylation on a precorrin intermediate. Because CbiE has sequence homology to canonical precorrin methyltransferases, CbiT was hypothesized to catalyze the decarboxylation. We herein present the crystal structure of MT0146, the CbiT homolog from Methanobacterium thermoautotrophicum. The protein shows structural similarity to Rossmann-like S-adenosyl-methionine-dependent methyltransferases, and our 1.9 A cocrystal structure shows that it binds S-adenosyl-methionine in standard geometry near a binding pocket that could accommodate a precorrin substrate. Therefore, MT0146/CbiT probably functions as a precorrin methyltransferase and represents the first enzyme identified with this activity that does not have the canonical precorrin methyltransferase fold. << Less

  Structure 10:1475-1487(2002) [PubMed] [EuropePMC]

  This publication is cited by 2 other entries.