Biosynthesis of vitamin B12: ring contraction is preceded by incorporation of molecular oxygen into precorrin-3

1993 ◽  
Vol 115 (24) ◽  
pp. 11610-11611 ◽  
Author(s):  
Jonathan B. Spencer ◽  
Neal J. Stolowich ◽  
Charles A. Roessner ◽  
Changhee Min ◽  
A. Ian Scott
Keyword(s):  
Vitamin B12 ◽  
Molecular Oxygen ◽  
Ring Contraction

scholarly journals Characterization of the Enzyme CbiH60Involved in Anaerobic Ring Contraction of the Cobalamin (Vitamin B12) Biosynthetic Pathway

2012 ◽  
Vol 288 (1) ◽  
pp. 297-305 ◽  
Author(s):  
Simon J. Moore ◽  
Rebekka Biedendieck ◽  
Andrew D. Lawrence ◽  
Evelyne Deery ◽  
Mark J. Howard ◽  
...  
Keyword(s):  
Vitamin B12 ◽  
Biosynthetic Pathway ◽  
Ring Contraction

Aerobic synthesis of vitamin B12: ring contraction and cobalt chelation

2005 ◽  
Vol 33 (4) ◽  
pp. 815-819 ◽  
Author(s):  
D. Heldt ◽  
A.D. Lawrence ◽  
M. Lindenmeyer ◽  
E. Deery ◽  
P. Heathcote ◽  
...  
Keyword(s):  
Vitamin B12 ◽  
Metal Ion ◽  
Biosynthetic Pathway ◽  
Rhodobacter Capsulatus ◽  
Chlorophyll Synthesis ◽  
Subsequent Reduction ◽  
Ring Contraction ◽  
Contraction Process ◽  
Cobalamin Biosynthesis ◽  
Haem Iron

The aerobic biosynthetic pathway for vitamin B12 (cobalamin) biosynthesis is reviewed. Particular attention is focused on the ring contraction process, whereby an integral carbon atom of the tetrapyrrole-derived macrocycle is removed. Previous work had established that this chemically demanding step is facilitated by the action of a mono-oxygenase called CobG, which generates a hydroxy lactone intermediate. This mono-oxygenase contains both a non-haem iron and an Fe-S centre, but little information is known about its mechanism. Recent work has established that in bacteria such as Rhodobacter capsulatus, CobG is substituted by an isofunctional protein called CobZ. This protein has been shown to contain flavin, haem and Fe-S centres. A mechanism is proposed to explain the function of CobZ. Another interesting aspect of the aerobic cobalamin biosynthetic pathway is cobalt insertion, which displays some similarity to the process of magnesium chelation in chlorophyll synthesis. The genetic requirements of cobalt chelation and the subsequent reduction of the metal ion are discussed.

scholarly journals Biosynthesis of vitamin B12: identity of fragment extruded during ring contraction to the corrin macrocycle.

1981 ◽  
Vol 78 (1) ◽  
pp. 13-15 ◽  
Author(s):  
A. R. Battersby ◽  
M. J. Bushell ◽  
C. Jones ◽  
N. G. Lewis ◽  
A. Pfenninger
Keyword(s):  
Vitamin B12 ◽  
Ring Contraction

Biosynthesis of vitamin B12: structure of precorrin-3B, the trimethylated substrate of the enzyme catalysing ring contraction

1993 ◽  
pp. 1100-1103 ◽  
Author(s):  
Laurent Debussche ◽  
Denis Thibaut ◽  
Martine Danzer ◽  
Fabrice Debu ◽  
Denise Fréchet ◽  
...  
Keyword(s):  
Vitamin B12 ◽  
Ring Contraction

(Invited) Climbing over the Activity Volcano Correlation by Biomimicking Vitamin B12: A Co Phthalocyanine Pyridine Axial Ligand Coordinated Catalyst for the Reduction of Molecular Oxygen

2018 ◽  
Vol 85 (12) ◽  
pp. 111-121 ◽  
Author(s):  
Jorge Riquelme ◽  
Karinna Neira ◽  
Jose F. Marco ◽  
Patricio Hermosilla ◽  
Diego Venegas ◽  
...  
Keyword(s):  
Vitamin B12 ◽  
Molecular Oxygen ◽  
Axial Ligand

Mechanism of the Ring Contraction Step in Vitamin B12 Biosynthesis: The Origin and Subsequent Fate of the Oxygen Functionalities in Precorrin-3x

1994 ◽  
Vol 116 (11) ◽  
pp. 4991-4992 ◽  
Author(s):  
Jonathan B. Spencer ◽  
Neal J. Stolowich ◽  
Patricio J. Santander ◽  
Clotilde Pichon ◽  
Masahiro Kajiwara ◽  
...  
Keyword(s):  
Vitamin B12 ◽  
Ring Contraction
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